crosvm.updateScript: don't vendor Cargo.lock

This is no longer required as crosvm now includes a Cargo.lock in-tree
again.

pkgs/applications/virtualization/crosvm/generate-cargo.sh

···
-dir="$(mktemp -d)" &&
-    cd "$dir" &&
-    unpackPhase &&
-    cd "${sourceRoot:-}" &&
-    cargo generate-lockfile &&
-    mv Cargo.lock "$1"
-rm -rf "$dir"

pkgs/applications/virtualization/crosvm/update.py

···
 
 # Update the version, git revision, and hash in crosvm's default.nix.
 subprocess.run(['update-source-version', 'crosvm', f'--rev={rev}', version])
-
-# Find the path to crosvm's default.nix, so Cargo.lock can be written
-# into the same directory.
-argv = ['nix-instantiate', '--eval', '--json', '-A', 'crosvm.meta.position']
-position = json.loads(subprocess.check_output(argv).decode('utf-8'))
-filename = re.match(r'[^:]*', position)[0]
-
-# Generate a Cargo.lock
-run = ['.',
-       dirname(abspath(__file__)) + '/generate-cargo.sh',
-       dirname(filename) + '/Cargo.lock']
-expr = '(import ./. {}).crosvm.overrideAttrs (_: { dontCargoSetupPostUnpack = true; })'
-subprocess.run(['nix-shell', '-E', expr, '--run', shlex.join(run)])