Extend Unofficial 1ES template in IdentityModel nightly tests job (#63466)

Co-authored-by: William Godbe <wigodbe@microsoft.com>

Author: github-actions[bot]

.azure/pipelines/identitymodel-helix-matrix.yml

@@ -24,7 +24,7 @@ resources:
     ref: refs/tags/release
 
 extends:
-  template: v1/1ES.Official.PipelineTemplate.yml@1esPipelines
+  template: v1/1ES.Unofficial.PipelineTemplate.yml@1esPipelines
   parameters:
     sdl:
       sourceAnalysisPool: