ci: also exclude top-level test/*.md from Codacy

Previous commit added `test/**/*.md`, but in gitignore-style globs
(which Codacy uses) `**` requires at least one subdirectory level,
so it does not match `test/REGRESSION.md` at the top of `test/`.
Codacy on bab42b8 still reported the 21 markdownlint findings.

Add `test/*.md` alongside `test/**/*.md` so both top-level and any
future subdirectory test markdown are excluded.

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

Author: etr

.codacy.yaml

@@ -9,4 +9,5 @@
 # regression gate at test/REGRESSION.md). Same rationale as specs/.
 exclude_paths:
   - 'specs/**'
+  - 'test/*.md'
   - 'test/**/*.md'