Bumps [cryptography](https://github.com/pyca/cryptography) from 44.0.1 to 44.0.2.
- [Changelog](https://github.com/pyca/cryptography/blob/main/CHANGELOG.rst)
- [Commits](pyca/cryptography@44.0.1...44.0.2)

---
updated-dependencies:
- dependency-name: cryptography
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Bumps [pytest](https://github.com/pytest-dev/pytest) from 8.3.4 to 8.3.5.
- [Release notes](https://github.com/pytest-dev/pytest/releases)
- [Changelog](https://github.com/pytest-dev/pytest/blob/main/CHANGELOG.rst)
- [Commits](pytest-dev/pytest@8.3.4...8.3.5)

---
updated-dependencies:
- dependency-name: pytest
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

* Add virtual environment management

* self test requirements are separated into sigstore-requirements.txt
* Makefile now creates a separate venv for selftest sigstore client
* sigstore-python-conformance expects to find the sigstore binary in the
  venv
* workflow is simplified similarly

Signed-off-by: Jussi Kukkonen <jkukkonen@google.com>

* Naming: change sigstore-env to selftest-env

This hopefully makes it clearer what it is. same goes
for selftest-requirements.txt

Signed-off-by: Jussi Kukkonen <jkukkonen@google.com>

---------

Signed-off-by: Jussi Kukkonen <jkukkonen@google.com>

Changelog is
* Use current sigstore-protobuf-specs
* Make sure the test suite is installed in a separate environment in
  both Makefile and the action

Signed-off-by: Jussi Kukkonen <jkukkonen@google.com>