fix: accept deps: as valid conventional commit type

Automated dependency bump PRs use `deps: bump devx...` as the commit
message, but the validator rejected `deps:` as it wasn't in the allowed
types list. This caused post-merge CI failures on grm and sso-bridge.

Implements: DEVX-165

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

tests/unit/test_validate_commit_msg.py

@@ -30,6 +30,7 @@ class TestHelpers:
         assert CONVENTIONAL_RE.match("test: add tests")
         assert CONVENTIONAL_RE.match("ci: update workflow")
         assert CONVENTIONAL_RE.match("build: update deps")
+        assert CONVENTIONAL_RE.match("deps: bump devx from v0.50.2 to v0.51.0")
         assert CONVENTIONAL_RE.match("revert: undo change")
 
     def test_conventional_re_allows_scope(self) -> None: