Update trigger and PR settings in YAML pipeline (#44392)

Co-authored-by: Juan Ospina <[email protected]>

Author: azure-sdk

eng/common/pipelines/ai-evals-tests.yml

@@ -1,6 +1,4 @@
-trigger: none
-
-pr:
+trigger:
   branches:
     include:
       - main
@@ -9,6 +7,8 @@ pr:
       - .github/copilot-instructions.md
       - eng/common/instructions/azsdk-tools/**
 
+pr: none
+
 parameters:
   - name: EvalProject
     type: string
@@ -45,4 +45,4 @@ extends:
     EvalRepoCommit: ${{ parameters.EvalRepoCommit }}
     TargetRepoOwner: $(TargetRepoOwner)
     TargetRepoName: $(TargetRepoName)
-    TargetRepoCommit: $(TargetRepoCommit)
+    TargetRepoCommit: $(TargetRepoCommit)