Git HTTP works with SSO Enforcement

What

Skips set_session_storage from GitHttpController to avoid us treating it as a web request and enforcing a SAML SSO session

Why

After enabling the enforced_sso_requires_session flag customers experienced failing pipelines. See https://gitlab.com/gitlab-com/gl-infra/infrastructure/issues/6750

Closes https://gitlab.com/gitlab-org/gitlab-ee/issues/11779

Conformity

• Changelog entry

Performance 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

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