ci: test scripts should fail on errors

While these test scripts are running in CI, if any of their commands
fail, they don't actually fail the build.

Author: BurntSushi

regex-syntax/test

@@ -1,5 +1,7 @@
 #!/bin/bash
 
+set -e
+
 # This is a convenience script for running a broad swath of the syntax tests.
 echo "===== DEFAULT FEATURES ==="
 cargo test

test

@@ -1,5 +1,7 @@
 #!/bin/bash
 
+set -e
+
 # This is a convenience script for running a broad swath of tests across
 # features. We don't test the complete space, since the complete space is quite
 # large. Hopefully once we migrate the test suite to better infrastructure