Update Widevine signature_generator to Python 3

[mherrmann]

We had to revert #18636 because init failed on Arm64 macOS with the output below.

Error output

17:13:16    writing manifest file 'src/cryptography.egg-info/SOURCES.txt'
17:13:16    /private/var/folders/hz/kc4099jd1czfj03q5t6xltlc0000gp/T/pip-build-env-g46jx2s4/overlay/lib/python3.8/site-packages/setuptools/command/build_py.py:201: _Warning: Package 'cryptography.hazmat.bindings._rust' is absent from the `packages` configuration.
17:13:16    !!
17:13:16    
17:13:16            ********************************************************************************
17:13:16            ############################
17:13:16            # Package would be ignored #
17:13:16            ############################
17:13:16            Python recognizes 'cryptography.hazmat.bindings._rust' as an importable package[^1],
17:13:16            but it is absent from setuptools' `packages` configuration.
17:13:16    
17:13:16            This leads to an ambiguous overall configuration. If you want to distribute this
17:13:16            package, please make sure that 'cryptography.hazmat.bindings._rust' is explicitly added
17:13:16            to the `packages` configuration field.
17:13:16    
17:13:16            Alternatively, you can also rely on setuptools' discovery methods
17:13:16            (for example by using `find_namespace_packages(...)`/`find_namespace:`
17:13:16            instead of `find_packages(...)`/`find:`).
17:13:16    
17:13:16            You can read more about "package discovery" on setuptools documentation page:
17:13:16    
17:13:16            - https://setuptools.pypa.io/en/latest/userguide/package_discovery.html
17:13:16    
17:13:16            If you don't want 'cryptography.hazmat.bindings._rust' to be distributed and are
17:13:16            already explicitly excluding 'cryptography.hazmat.bindings._rust' via
17:13:16            `find_namespace_packages(...)/find_namespace` or `find_packages(...)/find`,
17:13:16            you can try to use `exclude_package_data`, or `include-package-data=False` in
17:13:16            combination with a more fine grained `package-data` configuration.
17:13:16    
17:13:16            You can read more about "package data files" on setuptools documentation page:
17:13:16    
17:13:16            - https://setuptools.pypa.io/en/latest/userguide/datafiles.html
17:13:16    
17:13:16    
17:13:16            [^1]: For Python, any directory (with suitable naming) can be imported,
17:13:16                  even if it does not contain any `.py` files.
17:13:16                  On the other hand, currently there is no concept of package data
17:13:16                  directory, all directories are treated like packages.
17:13:16            ********************************************************************************
17:13:16    
17:13:16    !!
17:13:16      check.warn(importable)
17:13:16    copying src/cryptography/py.typed -> build/lib.macosx-11.0-arm64-cpython-38/cryptography
17:13:16    creating build/lib.macosx-11.0-arm64-cpython-38/cryptography/hazmat/bindings/_rust
17:13:16    copying src/cryptography/hazmat/bindings/_rust/__init__.pyi -> build/lib.macosx-11.0-arm64-cpython-38/cryptography/hazmat/bindings/_rust
17:13:16    copying src/cryptography/hazmat/bindings/_rust/asn1.pyi -> build/lib.macosx-11.0-arm64-cpython-38/cryptography/hazmat/bindings/_rust
17:13:16    copying src/cryptography/hazmat/bindings/_rust/ocsp.pyi -> build/lib.macosx-11.0-arm64-cpython-38/cryptography/hazmat/bindings/_rust
17:13:16    copying src/cryptography/hazmat/bindings/_rust/x509.pyi -> build/lib.macosx-11.0-arm64-cpython-38/cryptography/hazmat/bindings/_rust
17:13:16    warning: build_py: byte-compiling is disabled, skipping.
17:13:16    
17:13:16    running build_ext
17:13:16    generating cffi module 'build/temp.macosx-11.0-arm64-cpython-38/_openssl.c'
17:13:16    creating build/temp.macosx-11.0-arm64-cpython-38
17:13:16    running build_rust
17:13:16    cargo rustc --lib --message-format=json-render-diagnostics --manifest-path src/rust/Cargo.toml --release -v --features pyo3/abi3-py36 pyo3/extension-module --crate-type cdylib -- -C link-args=-undefined dynamic_lookup -Wl,-install_name,@rpath/_rust.abi3.so
17:13:16    error: rustup could not choose a version of cargo to run, because one wasn't specified explicitly, and no default is configured.
17:13:16    help: run 'rustup default stable' to download the latest stable release of Rust and set it as your default toolchain.
17:13:16    
17:13:16        =============================DEBUG ASSISTANCE=============================
17:13:16        If you are seeing a compilation error please try the following steps to
17:13:16        successfully install cryptography:
17:13:16        1) Upgrade to the latest pip and try again. This will fix errors for most
17:13:16           users. See: https://pip.pypa.io/en/stable/installing/#upgrading-pip
17:13:16        2) Read https://cryptography.io/en/latest/installation/ for specific
17:13:16           instructions for your platform.
17:13:16        3) Check our frequently asked questions for more information:
17:13:16           https://cryptography.io/en/latest/faq/
17:13:16        4) Ensure you have a recent Rust toolchain installed:
17:13:16           https://cryptography.io/en/latest/installation/#rust
17:13:16    
17:13:16        Python: 3.8.10
17:13:16        platform: macOS-13.3-arm64-arm-64bit
17:13:16        pip: n/a
17:13:16        setuptools: 68.0.0
17:13:16        setuptools_rust: 1.6.0
17:13:16        =============================DEBUG ASSISTANCE=============================
17:13:16    
17:13:16    error: `cargo rustc --lib --message-format=json-render-diagnostics --manifest-path src/rust/Cargo.toml --release -v --features 'pyo3/abi3-py36 pyo3/extension-module' --crate-type cdylib -- -C 'link-args=-undefined dynamic_lookup -Wl,-install_name,@rpath/_rust.abi3.so'` failed with code 1
17:13:16    ----------------------------------------
17:13:16    ERROR: Failed building wheel for cryptography

This PR contains the same changes as #18636, except for improved logic in DEPS.

[mherrmann]

@fmarier @simonhong can I please ask for your reviews? The only differences to #18636 are in DEPS.

[fmarier]

script/brave_license_helper.py 👍