CI: Avoid newer openssl version due to WMTS tests

The negotiation with a tile provider needed more up-to-date
TLS/SSL protocols, so for now we just pin to a lower openssl
on the runners.

.github/workflows/ci-testing.yml

@@ -51,6 +51,10 @@ jobs:
           PACKAGES="$PACKAGES owslib pep8 pillow pyshp pytest pytest-mpl"
           PACKAGES="$PACKAGES pytest-xdist setuptools_scm"
           PACKAGES="$PACKAGES setuptools_scm_git_archive shapely"
+          # openssl 3.0 updated the legacy renegotiation default, which causes
+          # failures in NASA's WMTS server. They will need to update their
+          # server before we can use a newer openssl.
+          PACKAGES="$PACKAGES openssl<3"
           conda install $PACKAGES
           conda info -a
           conda list