Update GitLab OIDC to SAML by default

[Racer159]

Is your feature request related to a problem? Please describe.

As Ezra I want SAML to be the default GitLab auth so that I can have a more secure default for larger environments.

Describe the solution you'd like

• Given I specify SSO to be on within the GitLab package
• And provide no additional bundle overrides
• When I deploy the package to the cluster
• Then GitLab will be configured to connect to Keycloak over SAML.

Describe alternatives you've considered

We could leave it as is with OIDC but this is less secure: https://github.com/defenseunicorns/uds-package-gitlab/blob/main/adr/0002-keycloak-integration.md#decision

Additional context

This should minimize breakage for consumers - an option to keep OIDC for those that have / want it should be considered.

[Racer159]

When doing this we should normalize this package with helm best practices and the new sonarqube package's way of doing things - namely providing consistent values keys for sso configuration (i.e. sso.enabled in the config chart)

This will be a breaking change so we should call that out in the release notes / PR (with a !)

[Racer159]

Ignore that previous comment - this is being done here: #115

[Racer159]

Normalization should still happen though where we still need to do it though

[ericwyles]

Need this PR merged and a new release of uds-core to finish testing. defenseunicorns/uds-identity-config#77

EDIT: PR to uds-identity-config is merged and included in uds-core main. Just waiting on uds-core next release.