Fix rubygem-irb upgrade not working due to directory -> symlink conversion.

Upgrade to Ruby 3.0.2.
Fix command injection vulnerability in RDoc. (CVE-2021-31799)
Fix FTP PASV command response can cause Net::FTP to connect to arbitrary host.
2021-31810)
Fix StartTLS stripping vulnerability in Net::IMAP (CVE-2021-32066)
Fix dependencies of gems with explicit source installed from a
2020-36327)
Pass ldflags to gem install via CONFIGURE_ARGS.
138 was wrong.

Upgrade to Ruby 3.0.1 by merging Fedora rawhide branch (commit: 6b2ff68).
Fix FTBFS due to an incompatible load directive.

Upgrade to Ruby 2.7.3.
Resolv::DNS: timeouts if multiple IPv6 name servers are given and address

Upgrade to Ruby 2.7.2.
Avoid possible timeout errors in TestBugReporter#test_bug_reporter_add.

Fix `require` behavior allowing to load libraries multiple times.
Add ruby-default-gems dependency on irb.

Ship racc binary.

Update to Ruby 2.7.1 by merging Fedora master branch (commit: 2981648)

Use ffi_closure_alloc to avoid segmentation fault by libffi on aarch64.
Properly support %prerelease in %gemspec_ macros.

Update to Ruby 2.6.3 by merging Fedora master branch (commit: 1cc2a49)

Update to Ruby 2.5.5.
TLS-1.3.patch; subsumed
Don't ship .stp files when SystemTap support is disabled.
Fix CovScan issues.

Refresh expired certificates to fix FTBFS.

Fix Tokyo TZ tests.

Update to Ruby 2.5.3.

Properly harden package using -fstack-protector-strong.

Additional OpenSSL 1.1.1 fixes.