Normalize rusty_v8 checksum manifest line endings (#36797)

## What changed

- Write staged `rusty_v8` checksum manifests with LF line endings on every platform.
- Strip carriage returns when verifying manifests so existing Windows-built releases with CRLF line endings remain usable.

## Testing

- Assert that staged checksum manifests contain no carriage returns.

GitOrigin-RevId: 142855c147a08a60f5e5782c61e2fcd6b2e350d6

.github/actions/setup-rusty-v8/action.yml

@@ -44,10 +44,11 @@ runs:
           exit 1
         fi
 
+        # Existing Windows-built release manifests use CRLF line endings.
         if command -v sha256sum >/dev/null 2>&1; then
-          (cd "${binding_dir}" && sha256sum -c "${checksums_path}")
+          (cd "${binding_dir}" && tr -d '\r' < "${checksums_path}" | sha256sum -c -)
         else
-          (cd "${binding_dir}" && shasum -a 256 -c "${checksums_path}")
+          (cd "${binding_dir}" && tr -d '\r' < "${checksums_path}" | shasum -a 256 -c -)
         fi
         echo "RUSTY_V8_ARCHIVE=${archive_path}" >> "${GITHUB_ENV}"
         echo "RUSTY_V8_SRC_BINDING_PATH=${binding_path}" >> "${GITHUB_ENV}"

.github/scripts/rusty_v8_bazel.py

@@ -245,7 +245,7 @@ def stage_artifacts(
     shutil.copyfile(binding_path, staged_binding)
 
     staged_checksums = output_dir / staged_checksums_name(target, artifact_profile)
-    with staged_checksums.open("w", encoding="utf-8") as checksums:
+    with staged_checksums.open("w", encoding="utf-8", newline="\n") as checksums:
         for path in [staged_library, staged_binding]:
             digest = hashlib.sha256()
             with path.open("rb") as artifact:

.github/scripts/test_rusty_v8_bazel.py

@@ -191,6 +191,11 @@ class RustyV8BazelTest(unittest.TestCase):
                 },
                 {path.name for path in Path(output_dir).iterdir()},
             )
+            checksums = (
+                Path(output_dir)
+                / "rusty_v8_ptrcomp_sandbox_release_aarch64-apple-darwin.sha256"
+            ).read_bytes()
+            self.assertNotIn(b"\r", checksums)
 
     def test_upstream_release_pair_paths(self) -> None:
         self.assertEqual(