Extend Unofficial 1ES template in IdentityModel nightly tests job (#63468)

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

Author: github-actions[bot]

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

@@ -26,7 +26,7 @@ resources:
  ref: refs/tags/release
 
 extends:
- template: v1/1ES.Official.PipelineTemplate.yml@1esPipelines
+ template: v1/1ES.Unofficial.PipelineTemplate.yml@1esPipelines
  parameters:
  sdl:
  sourceAnalysisPool: