Apply suggestions from code review

Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
Co-authored-by: Ezio Melotti <ezio.melotti@gmail.com>

Author: 3 people

run_release.py

@@ -490,7 +490,7 @@ def test_release_artifacts(db: DbfilenameShelf) -> None:
 
 def build_sbom_artifacts(db):
 
-    # Skip building an SBOM if there isn't an 'Misc/sbom.spdx.json' file.
+    # Skip building an SBOM if there isn't a 'Misc/sbom.spdx.json' file.
     if not (db["git_repo"] / "Misc/sbom.spdx.json").exists():
         print("Skipping building an SBOM, missing 'Misc/sbom.spdx.json'")
         return

sbom.py

@@ -293,10 +293,10 @@ def create_sbom_for_source_tarball(tarball_path: str):
     return sbom
 
 
-if __name__ == "__main__":
+def main() -> None:
     tarball_path = sys.argv[1]
-    print(
-        json.dumps(
-            create_sbom_for_source_tarball(tarball_path), indent=2, sort_keys=True
-        )
-    )
+    sbom_data = create_sbom_for_source_tarball(tarball_path)
+    print(json.dumps(sbom_data, indent=2, sort_keys=True))
+
+if __name__ == "__main__":
+    main()