build(deps): bump install-pinned/mypy

Bumps [install-pinned/mypy](https://github.com/install-pinned/mypy) from 2b7ed3821d580865e560636733cce75157624e34 to 812c1e7b83dc0b678bdb1c0610d937077c32615e.
- [Release notes](https://github.com/install-pinned/mypy/releases)
- [Commits](install-pinned/mypy@2b7ed38...812c1e7)

---
updated-dependencies:
- dependency-name: install-pinned/mypy
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/pyapi.yml

@@ -91,7 +91,7 @@ jobs:
       - name: Install maturin from PyPI
         uses: install-pinned/maturin@ab13013f30551a87b56c6a9c2bdd7b6287581def
       - name: Install mypy from PyPI
-        uses: install-pinned/mypy@2b7ed3821d580865e560636733cce75157624e34
+        uses: install-pinned/mypy@812c1e7b83dc0b678bdb1c0610d937077c32615e
       - name: Install python project
         run: maturin build -m pyapi/Cargo.toml && pip install --no-index --find-links target/wheels/ rustsat
       - name: Test stubs