Support Google SSO

[cakecatz]

What would you like to be added:

Why is this needed:

[nghialv]

/assign @ono-max

[github-actions[bot]]

This issue is stale because it has been open 180 days with no activity. Remove stale label or comment or this will be closed in 7 days.

[github-actions[bot]]

This issue was closed because it has been stalled for 7 days with no activity. Feel free to reopen if still applicable.

[ffjlabo]

Reopen the issue because there is demand for Google SSO.

[Status]

• Currently, we don't support the Google SSO, only GitHub SSO. https://github.com/pipe-cd/pipecd/blob/d36287904f5c0e0980f50f0dd99534ada0eee008/pkg/app/server/httpapi/callback.go#L140-L155
• But there are some documents about it.
  • https://pipecd.dev/docs-v0.48.x/user-guide/managing-controlplane/configuration-reference/#sharedssoconfig
  • https://pipecd.dev/docs-v0.48.x/user-guide/managing-controlplane/auth/#single-sign-on-sso
• Another contributor tries to support the OIDC feature for SSO https://github.com/pipe-cd/pipecd/issues/4906