LUCENE-7935 we added .sha512 checksums to releases and removed .md5 files.
According to the Release Distribution Policy (http://www.apache.org/dev/release-distribution#sigs-and-sums):
For every artifact distributed to the public through Apache channels, the PMC
MUST supply a valid OpenPGP-compatible ASCII-armored detached signature file
MUST supply at least one checksum file
SHOULD supply a SHA-256 and/or SHA-512 checksum file
SHOULD NOT supply a MD5 or SHA-1 checksum file (because these are deprecated)
So this Jira will stop publishing .sha1 files, leaving only the .sha512