Update MetadataFactory.py to force IPV4 (not IPV6)

requested review from @bgeels

assigned to @erigler

Does the IPV4 issue also affect WebAbsolutesFactory? I see that we use urllib there instead of requests but I don't know how much we use WebAbsolutesFactory in the adjusted pipeline.

Approving. The question above is related but the MR doesn't depend on it.

approved this merge request

resolved all threads

mentioned in commit 87e225c8

merged