chore(3p/overlays/tvl): switch to nixpkgs crate2nix

Since a recent nixpkgs bump bringing a version of cargo with
rust-lang/cargo#12914,
crate2nix creates a crate-hashes.json with all crate hashes from
Cargo.lock (and downloads a lot of stuff while producing it).

nix-community/crate2nix#341 prevents this from
happening, but our hardcoded crate2nix pin prevented us from getting the
fix included in 0.14.0, which did land in nixpkgs.

Replace the pin with a simply override, carrying our only leftover patch
on top of it, and link to that PR.

Change-Id: I9503898e15d61fa6a2b1589d141bec1b4ed3d616
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11581
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>

Cargo.nix

@@ -1,4 +1,4 @@
-# This file was @generated by crate2nix 0.13.0 with the command:
+# This file was @generated by crate2nix 0.14.0 with the command:
 #   "generate" "--all-features"
 # See https://github.com/kolloch/crate2nix for more info.
 
@@ -17085,8 +17085,9 @@ rec {
             # because we compiled those test binaries in the former and not the latter.
             # So all paths will expect source tree to be there and not in the build top directly.
             # For example: $NIX_BUILD_TOP := /build in general, if you ask yourself.
-            # TODO(raitobezarius): I believe there could be more edge cases if `crate.sourceRoot`
-            # do exist but it's very hard to reason about them, so let's wait until the first bug report.
+            # NOTE: There could be edge cases if `crate.sourceRoot` does exist but
+            # it's very hard to reason about them.
+            # Open a bug if you run into this!
             mkdir -p source/
             cd source/
 

crate-hashes.json

@@ -1,4 +1,4 @@
 {
-  "bigtable_rs 0.2.9 (git+https://github.com/flokli/bigtable_rs?rev=0af404741dfc40eb9fa99cf4d4140a09c5c20df7#0af404741dfc40eb9fa99cf4d4140a09c5c20df7)": "1njjam1lx2xlnm7a41lga8601vmjgqz0fvc77x24gd04pc7avxll",
-  "wu-manber 0.1.0 (git+https://github.com/tvlfyi/wu-manber.git#0d5b22bea136659f7de60b102a7030e0daaa503d)": "1zhk83lbq99xzyjwphv2qrb8f8qgfqwa5bbbvyzm0z0bljsjv0pd"
+  "git+https://github.com/flokli/bigtable_rs?rev=0af404741dfc40eb9fa99cf4d4140a09c5c20df7#0.2.9": "1njjam1lx2xlnm7a41lga8601vmjgqz0fvc77x24gd04pc7avxll",
+  "git+https://github.com/tvlfyi/wu-manber.git#wu-manber@0.1.0": "1zhk83lbq99xzyjwphv2qrb8f8qgfqwa5bbbvyzm0z0bljsjv0pd"
 }