adding invalid test to CI

Author: Kbz-8

.github/workflows/build.yml

@@ -32,3 +32,4 @@ jobs:
           cd test
           /usr/bin/bash build.sh
           ./valid
+          ./invalid

test/invalid_test.c

@@ -19,9 +19,9 @@ int main(void)
 		fprintf(stderr, "%s\n", error);
 		wgsl_validator_free_error(error);
 		wgsl_validator_destroy(validator);
-		return 1;
+		return 0;
 	}
 	wgsl_validator_destroy(validator);
-	puts("Successfully parsed shader");
-	return 0;
+	fprintf(stderr, "Successfully parsed shader (Should not have happened)\n");
+	return 1;
 }