[release/v7.4] Disable SBOM generation on set variables job in release build (PowerShell#25341)

Co-authored-by: Aditya Patwardhan <adityap@microsoft.com>

Author: pwshBot

.pipelines/PowerShell-Coordinated_Packages-Official.yml

@@ -137,6 +137,8 @@ extends:
             value: $(Build.SourcesDirectory)\PowerShell\.config\tsaoptions.json
           - name: ob_signing_setup_enabled
             value: false
+          - name: ob_sdl_sbom_enabled
+            value: false
 
         steps:
         - checkout: self