fix(ci): map @TheGardenGallery email + drop unused pytest import

- check-attribution: add chilltulpa@gmail.com -> TheGardenGallery to
  AUTHOR_MAP in scripts/release.py (new external contributor via the
  carried-over commits).
- ty: the dashboard back-compat test imported pytest but never used it,
  tripping unresolved-import. Drop the dead import — tests are plain
  functions driving the parser via subprocess, no pytest API needed.

scripts/release.py

@@ -45,6 +45,7 @@ ACP_REGISTRY_MANIFEST = REPO_ROOT / "acp_registry" / "agent.json"
 
 # Auto-extracted from noreply emails + manual overrides
 AUTHOR_MAP = {
+    "chilltulpa@gmail.com": "TheGardenGallery",
     "al@randomsnowflake.me": "randomsnowflake",
     "834740219@qq.com": "ViewWay",
     "harjoth.khara@gmail.com": "harjothkhara",