GitLab is an OpenIdConnectApi

Signed-off-by: Jamie Klassen <jklassen@vmware.com>

.changeset/young-walls-prove.md

@@ -0,0 +1,5 @@
+---
+'@backstage/core-plugin-api': minor
+---
+
+The GitLab auth provider can now be used to get OpenID tokens.

packages/core-plugin-api/api-report.md

@@ -482,7 +482,11 @@ export const githubAuthApiRef: ApiRef<
 
 // @public
 export const gitlabAuthApiRef: ApiRef<
-  OAuthApi & ProfileInfoApi & BackstageIdentityApi & SessionApi
+  OAuthApi &
+    OpenIdConnectApi &
+    ProfileInfoApi &
+    BackstageIdentityApi &
+    SessionApi
 >;
 
 // @public

packages/core-plugin-api/src/apis/definitions/auth.ts

@@ -357,7 +357,11 @@ export const oktaAuthApiRef: ApiRef<
  * for a full list of supported scopes.
  */
 export const gitlabAuthApiRef: ApiRef<
-  OAuthApi & ProfileInfoApi & BackstageIdentityApi & SessionApi
+  OAuthApi &
+    OpenIdConnectApi &
+    ProfileInfoApi &
+    BackstageIdentityApi &
+    SessionApi
 > = createApiRef({
   id: 'core.auth.gitlab',
 });

packages/integration-react/api-report.md

@@ -23,7 +23,11 @@ export class ScmAuth implements ScmAuthApi {
     ScmAuthApi,
     {
       github: OAuthApi & ProfileInfoApi & BackstageIdentityApi & SessionApi;
-      gitlab: OAuthApi & ProfileInfoApi & BackstageIdentityApi & SessionApi;
+      gitlab: OAuthApi &
+        OpenIdConnectApi &
+        ProfileInfoApi &
+        BackstageIdentityApi &
+        SessionApi;
       azure: OAuthApi &
         OpenIdConnectApi &
         ProfileInfoApi &