Truncate test result files

Problem: The NFR tests need to update the edge results, but they are
appending the new results to the existing ones

Solution: Truncate existing results files so that the content is replaced
and we see the diff in the PR

.github/workflows/nfr.yml

@@ -159,6 +159,7 @@ jobs:
         uses: actions/download-artifact@fa0a91b85d4f404e444e00e005971372dc801d16 # v4.1.8
         with:
           path: tests/results/
+          merge-multiple: true
 
       - name: Open a PR with the results
         uses: peter-evans/create-pull-request@c5a7806660adbe173f04e3e038b0ccdcd758773c # v6.1.0

tests/framework/results.go

@@ -25,7 +25,7 @@ func CreateResultsDir(testName, version string) (string, error) {
 
 // CreateResultsFile creates and returns the results file for a test.
 func CreateResultsFile(filename string) (*os.File, error) {
-	outFile, err := os.OpenFile(filename, os.O_APPEND|os.O_WRONLY|os.O_CREATE, 0o777)
+	outFile, err := os.OpenFile(filename, os.O_TRUNC|os.O_WRONLY|os.O_CREATE, 0o644)
 	if err != nil {
 		return nil, err
 	}