python: fix msys64 wheel directory specification

In python3.14, fixes were made to the file URI parsing [1] such that
file URIs that used to work but were technically out of spec are now
broken.

As a result, our msys2 GitLab CI tests began failing.

Stop using "file://" URI links in favor of simple paths (Thanks pbo) to
fix parsing errors under Python 3.14 and fix the msys2 GitLab CI tests.

[1] https://docs.python.org/3/whatsnew/3.14.html#urllib

Reported-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Suggested-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Tested-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20260130050518.517688-2-jsnow@redhat.com>

python/scripts/mkvenv.py

@@ -683,7 +683,7 @@ def pip_install(
     if not online:
         full_args += ["--no-index"]
     if wheels_dir:
-        full_args += ["--find-links", f"file://{str(wheels_dir)}"]
+        full_args += ["--find-links", str(wheels_dir)]
     full_args += list(args)
     subprocess.run(
         full_args,