Read flaky-test-fix model from its progress branch

Author: trask

.github/workflows/flaky-test-fix.yml

@@ -110,11 +110,8 @@ jobs:
       - name: Resolve Copilot model
         id: model
         run: |
-          git fetch origin otelbot/code-review-progress || true
-          model=$(git show origin/otelbot/code-review-progress:model.txt 2>/dev/null | xargs || true)
-          if [[ -z "$model" ]]; then
-            model="gpt-5.5"
-          fi
+          git fetch origin otelbot/flaky-test-fix-progress
+          model=$(git show origin/otelbot/flaky-test-fix-progress:model.txt | xargs)
           echo "model=$model" >> "$GITHUB_OUTPUT"
 
       - name: Check out fix branch