image-tests: skip tests if the test case cannot be opened

Schutzbot currently runs all the same tests an all arches/distro
combinations. This will not work as we introduce image types only on
some distro/arches.

In the future we should make the image-test binary more clever, so
Schutzbot won't have to tell it which cases to run at all. For now,
simply don't fail if the specified test-case does not exist.

Signed-off-by: Tom Gundersen <teg@jklm.no>

cmd/osbuild-image-tests/main_test.go

@@ -399,7 +399,9 @@ func runTests(t *testing.T, cases []string) {
 	for _, path := range cases {
 		t.Run(path, func(t *testing.T) {
 			f, err := os.Open(path)
-			require.NoErrorf(t, err, "%s: cannot open test case: %#v", path, err)
+			if err != nil {
+				t.Skipf("%s: cannot open test case: %#v", path, err)
+			}
 
 			var testcase testcaseStruct
 			err = json.NewDecoder(f).Decode(&testcase)