fix(tests): Don't assume release is set

[sentrivana]

Description

Even though we try to figure out the current release automatically if it's not provided, it can still end up being None. If that's the case, it won't be attached to logs. The test_logs_attributes test assumes there always is a release, which is incorrect.

I opted for conditionally checking for sentry.release in the test instead of removing the check altogether, even though the test itself is supposed to test custom user provided attributes. The reason is that there is no other generic logs test testing sentry.release.

Issues

Closes #4878

Reminders

• Please add tests to validate your changes, and lint your code using tox -e linters.
• Add GH Issue ID & Linear ID (if applicable)
• PR title should use conventional commit style (feat:, fix:, ref:, meta:)
• For external contributors: CONTRIBUTING.md, Sentry SDK development docs, Discord community