fix(ci): pin dogfood workflow to semvertag>=0.3.1

0.3.0's branch-prefix strategy doesn't recognize GitHub PR merge
subjects; the dogfood workflow silently no-op'd on every merge.
0.3.1 fixed this. Tighten the floor so the workflow can't resolve
to the known-broken 0.3.0.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: lesnik512

.github/workflows/semvertag.yml

@@ -31,7 +31,7 @@ jobs:
         with:
           python-version: "3.13"
       - run: pip install --quiet --no-cache-dir 'uv>=0.4,<1'
-      - run: uvx 'semvertag>=0.3,<1' tag
+      - run: uvx 'semvertag>=0.3.1,<1' tag
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           SEMVERTAG_BRANCH_PREFIX__MINOR: '["feat/"]'