Add github_tags auto method (#427)

Add a new method to fetch tags with their related commit date using GitHub GraphQL API.

For large repositories, such as https://github.com/gregkh/linux, it may be more performant than the git auto method.

src/common/github.py

@@ -11,6 +11,12 @@ class Release:
         self.is_prerelease: bool = is_prerelease
 
 
+class Tag:
+    def __init__(self, name: str, commit_at: str) -> None:
+        self.name: str = name
+        self.commit_date: str = commit_at
+
+
 def fetch_releases(repo_id: str) -> list[Release]:
     logging.info(f"fetching {repo_id} GitHub releases")
     (owner, repo) = repo_id.split('/')
@@ -48,3 +54,41 @@ query($endCursor: String) {
                                     release_data['isPrerelease']))
 
     return releases
+
+def fetch_tags(repo_id: str) -> list[Tag]:
+    logging.info(f"fetching {repo_id} tags")
+    (owner, repo) = repo_id.split('/')
+    child = subprocess.run("""gh api graphql --paginate -f query='
+query($endCursor: String) {
+  repository(name: "%s", owner: "%s") {
+    refs(refPrefix: "refs/tags/", first: 100, after: $endCursor) {
+      pageInfo { hasNextPage, endCursor }
+      edges {
+        node {
+          name
+          target {
+            ... on Tag {
+              tagger {
+                date
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+}'""" % (repo, owner), capture_output=True, timeout=300, check=True, shell=True)  # noqa: UP031
+    logging.info(f"fetched {repo_id} tags")
+
+    responses = child.stdout.decode("utf-8").strip().replace('}{', '}\n{').split("\n")
+    pages = [json.loads(response) for response in responses]
+
+    tags = []
+    for page in pages:
+        for edge in page['data']['repository']['refs']['edges']:
+            tag_name = edge['node']['name']
+            tags_date = edge['node']['target'].get('tagger', {}).get('date', None)
+            if tags_date:
+                tags.append(Tag(tag_name, tags_date))
+
+    return tags