fix: add apple as identity provider type to settings v2 api (#8472)

# Which Problems Are Solved

Apple is not availabe as IDP type in the settings v2 API.

# How the Problems Are Solved

Add Apple as type.

# Additional Changes

None

# Additional Context

None

Co-authored-by: Max Peintner <max@caos.ch>

internal/api/grpc/settings/v2/settings_converter_test.go

@@ -466,6 +466,10 @@ func Test_idpTypeToPb(t *testing.T) {
 			args: args{domain.IDPTypeGoogle},
 			want: settings.IdentityProviderType_IDENTITY_PROVIDER_TYPE_GOOGLE,
 		},
+		{
+			args: args{domain.IDPTypeApple},
+			want: settings.IdentityProviderType_IDENTITY_PROVIDER_TYPE_APPLE,
+		},
 		{
 			args: args{domain.IDPTypeSAML},
 			want: settings.IdentityProviderType_IDENTITY_PROVIDER_TYPE_SAML,