Changelog for librepo: 1.20.0 -> 1.21.0

5e5bdda use PROV for pkcs11 URIs with OpenSSL 4.x
54e8496 test: verify missing key error message consistency across backends
ea33d57 gpgme: report "Signing key not found" when signing key is missing
13e2a9b PGP: define shared error message constants for both backends
f756add Optionally build librepo as a static library as well
adf4afa test: don't expect empty file when downloading fails
84ce760 Fix metadata file descriptor leaks
ec49f22 Close zchunk seed fd in find_local_zck_header
a42277a Do not fail in lr_prepare_repodata_dir() if repodata/ dir exists
84206b2 Fix download resume within a single session
23a958f Configure packit to use caret notation for postrelease snapshots
9e5b003 Set CMAKE_SKIP_RPATH to TRUE
5d8b0ea Fix memory leaks in `lr_yum_download_repos`
e39ef74 Fix: actually store metalink and mirrorlist download targets
9eff2fc PGP: Fix creating /run/gnupg/user
731b5f9 Replace deprecated CURLOPT_PROGRESSFUNCTION
be788e8 spec: Postrelease version bump
5d52606 gpgme: Improve handling of expired GPG signatures with key rotation support
067e0ea Merge packit copr_build jobs into one
310d247 CI: Correct a link to packit documentation
03a20b2 Add build requirements installation instructions
0fc4b98 Test importing keys with prefix and suffix
a260f21 We cannot build for epel-8 due to glib2 ≥ 2.66 requirement
f22fc30 Add packit copr-builds and tests