chore(deps): bump mkdocs-material 9.7.0 -> 9.7.7 (CVE-2026-73295)

Patch-level upgrade closing the sole remaining pip-audit finding
attributable to a project dependency (docs/dev-only, not shipped in
the runtime). Sole remaining cause of CI red after 7ce0f60/a64256a9.

Verified: poetry run pip-audit now reports only the pip bootstrap
vulnerability (PYSEC-2026-3721), which CI's own "Upgrade pip in Poetry
venv" step already resolves in that environment; pip itself is
untouched here per scope. poetry run mkdocs build --clean exits 0.
Lockfile diff is limited to mkdocs-material's own version/hash/
dependency-bound metadata plus the content-hash -- no unrelated
package churn.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Author: DariuszNewecki

poetry.lock

@@ -143,7 +143,7 @@ httpx = "^0.28.1"
 ipython = "^8.12"
 anyio = "^4.11.0"
 mkdocs = "^1.6.1"
-mkdocs-material = "^9.7.0"
+mkdocs-material = "^9.7.7"
 vulture = "^2.14"
 pip-audit = "^2.10.1"
 bandit = "^1.9.2"