submodules: update clippy from a20599a to 71ec4ff

Should fix clippy toolstat.

Changes:

````
rustup #55330
Update stderr
Rename test files
Also lint cfg_attr(.., rustfmt::skip)
Add tests from rustfmt::skip test file
Run update_lints.py script
Add test for non-crate-level inner attributes
Differ between inner and outer attributes
Add tests
Add cfg_attr(rustfmt) lint
Addressed comments.
Fix dogfood error.
Added lints `into_iter_on_ref` and `into_iter_on_array`. Fix #1565.
Allow single_match_else
Update stderr
Add copyright statement©
Fix typos
Fix dogfood error
Fix typo and indentation
run update_lints script
Add tests for unknwon_clippy_lints lint
Add new lint: unknwon_clippy_lintsg
clippy: fix pedantic warnings and run clippy::pedantic lints on the codebase.
Fix a false-positive of needless_borrow
UI test cleanup: Extract match_overlapping_arm tests
UI test cleanup: Extract expect_fun_call tests
Add missing code of conduct file
Use slice patterns instead of padding
Fix dogfood and pedantic lints
ci: when installing rust-toolchain-installer-master, install it in debug mode to save some time in ci.
RIIR update lints: Generate deprecated lints
Replace big if/else expression with match
````

Author: matthiaskrgr