GRM-45: fix: badge regex patterns and doc_coverage double-percent

Two issues caused coverage and docs badges to show "unknown":

1. Coverage regex expected decimal (100.00%) but pytest-cov outputs
   100% when coverage is exactly 100. Made decimal part optional.

2. doc_coverage.py passed pct="100%" to a template that already had
   %, producing (100%%). Removed the redundant % from the pct variable.
   Also relaxed the doc coverage regex to not require closing ).

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scripts/ci/doc_coverage.py

@@ -145,7 +145,7 @@ def main(docs_dir: str, fail_on_missing: bool) -> None:
             "\nDoc coverage: {covered}/{total} ({pct}%)",
             covered=covered,
             total=total,
-            pct=f"{percentage:.0f}%",
+            pct=f"{percentage:.0f}",
         )
     )