Note: pin of urlchecker

This is a reminder:

urlchecker was pinned to 0.0.34 with !61 (merged) because version 0.0.35 could not handle those two URLs and marked them as offline even though they were reachable:

🤔 Uh oh... The following urls did not pass:
❌️ https://zenodo.org/badge/832612594.svg
❌️ https://earth-search.aws.element84.com/v1
make: *** [Makefile:64: urlcheck] Error 1
Cleaning up file based variables 00:05
ERROR: Job failed: exit code 1