Provide fix for inconsistent blocking of sso-user git actions

What does this MR do?

In !56867 (merged) I introduced check: if sso-user wanted to perform git action, I was checking if there is an active sso-session for this user and provider connected to this group/project.

There were some comments about problems with this feature: #9152 (comment 556178296)

I think the problem is that when there are more than one session open for a user I was not picking up the latest one. I believe it would affect users with enforced_sso_expiry feature flag switched on.

Screenshots (strongly suggested)

Does this MR meet the acceptance criteria?

Conformity

• 📋 Does this MR need a changelog?
  • I have included a changelog entry.
  • I have not included a changelog entry because _____.
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team

Related to #9152 (closed)