Chunks from Maven / Ivy repositories, used by coursier during its tests.

To update those, run JVM tests in coursier with FETCH_MOCK_DATA=1 in the environment.

$ FETCH_MOCK_DATA=1 ./mill 'tests.jvm[2.12.18].test.testOnly' coursier.tests.CentralTests

Then go to its tests/metadata directory (which is a git submodule), (git) add the newly-created files, commit that, push the result somewhere, open a PR here.