Retire unused weather bundle persistence helpers

internal/fileutil/fileutil_test.go

@@ -150,19 +150,3 @@ func TestWriteFileAtomicContextPreservesDestinationWhenCanceledAtPublication(t *
 		t.Fatalf("temporary files/error = %v/%v", matches, globErr)
 	}
 }
-
-func TestWriteJSONAtomic(t *testing.T) {
-	path := filepath.Join(t.TempDir(), "artifact.json")
-
-	if err := WriteJSONAtomic(path, map[string]string{"status": "ok"}); err != nil {
-		t.Fatalf("WriteJSONAtomic() error = %v", err)
-	}
-
-	data, err := os.ReadFile(path)
-	if err != nil {
-		t.Fatalf("ReadFile() error = %v", err)
-	}
-	if string(data) != "{\n  \"status\": \"ok\"\n}" {
-		t.Fatalf("json = %q, want indented object", data)
-	}
-}