Bump the pip group with 2 updates

Bumps the pip group with 2 updates: [python-gnupg](https://github.com/vsajip/python-gnupg) and [sigstore](https://github.com/sigstore/sigstore-python).


Updates `python-gnupg` from 0.5.5 to 0.5.6
- [Release notes](https://github.com/vsajip/python-gnupg/releases)
- [Changelog](https://github.com/vsajip/python-gnupg/blob/master/release)
- [Commits](vsajip/python-gnupg@0.5.5...0.5.6)

Updates `sigstore` from 3.6.5 to 3.6.6
- [Release notes](https://github.com/sigstore/sigstore-python/releases)
- [Changelog](https://github.com/sigstore/sigstore-python/blob/main/CHANGELOG.md)
- [Commits](sigstore/sigstore-python@v3.6.5...v3.6.6)

---
updated-dependencies:
- dependency-name: python-gnupg
  dependency-version: 0.5.6
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: pip
- dependency-name: sigstore
  dependency-version: 3.6.6
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: pip
...

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

Author: dependabot[bot]

mypy-requirements.txt

@@ -5,6 +5,6 @@ pyfakefs
 pytest
 pytest-mock
 python-gnupg  # untyped :(
-sigstore==3.6.5
+sigstore==3.6.6
 types-paramiko
 types-requests

requirements.txt

@@ -888,8 +888,8 @@ pyopenssl==25.0.0 \
 python-dateutil==2.9.0.post0 \
     --hash=sha256:a8b2bc7bffae282281c8140a97d3aa9c14da0b136dfe83f850eea9a5f7470427
     # via betterproto
-python-gnupg==0.5.5 \
-    --hash=sha256:51fa7b8831ff0914bc73d74c59b99c613de7247b91294323c39733bb85ac3fc1
+python-gnupg==0.5.6 \
+    --hash=sha256:b5050a55663d8ab9fcc8d97556d229af337a87a3ebebd7054cbd8b7e2043394a
     # via -r requirements.in
 requests==2.32.4 \
     --hash=sha256:27babd3cda2a6d50b30443204ee89830707d396671944c998b5975b031ac2b2c