Update approvaltests requirement from ~=11.0 to ~=12.0

Updates the requirements on [approvaltests](https://github.com/approvals/ApprovalTests.Python) to permit the latest version.
- [Release notes](https://github.com/approvals/ApprovalTests.Python/releases)
- [Commits](approvals/ApprovalTests.Python@v11.0.0...v12.0.0)

---
updated-dependencies:
- dependency-name: approvaltests
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

pyproject.toml

@@ -58,7 +58,7 @@ dynamic = ["version"]
 
 [project.optional-dependencies]
 tests = [
-    "approvaltests~=11.0",
+    "approvaltests~=12.0",
     "flake8~=7.0",
     "pylint~=3.1",
     "pytest~=8.0",