cpp-linter and clang-tools were pinned with exact == constraints in the action dependency group, causing Dependabot to report "No update possible" — uv lock --upgrade-package cannot change the lockfile when the specifier only allows one exact version.

Changes

• pyproject.toml: Change action group deps from exact (==) to minimum-version (>=) constraints, consistent with dev/docs groups. The lockfile still pins the runtime version precisely.
• uv.lock: Regenerated with uv lock --upgrade-package cpp-linter, bumping cpp-linter to 1.12.1 for Python ≥ 3.10 (stays at 1.12.0 for Python < 3.10, as 1.12.1 transitively requires pygit2 ≥ 1.19.2 which dropped 3.9 support).

# before
action = [
    "clang-tools==0.17.0",
    "cpp-linter==1.12.0",
]

# after
action = [
    "clang-tools>=0.17.0",
    "cpp-linter>=1.12.0",
]