Remove libre2 from build

With the update to re2 gem v2.0 in
https://gitlab.com/gitlab-org/gitlab/-/merge_requests/131273, we no
longer need to build and ship libre2. The gem handles the building and
compiling of all dependencies (libre2 and abseil-cpp), and it also
ships with precompiled gems.

This unblocks upgrades to the `grpc` gem since
grpc/grpc#33615 no longer applies.

Changelog: changed

Author: stanhu

.custom_sources.yml

@@ -103,9 +103,6 @@ libicu:
 krb5:
   remote: "[email protected]:omnibus-mirror/krb5.git"
   alternative: "https://gitlab.com/gitlab-org/build/omnibus-mirror/krb5.git"
-libre2:
-  remote: "[email protected]:omnibus-mirror/libre2.git"
-  alternative: "https://gitlab.com/gitlab-org/build/omnibus-mirror/libre2.git"
 libpng:
   remote: "[email protected]:omnibus-mirror/libpng.git"
   alternative: "https://gitlab.com/gitlab-org/build/omnibus-mirror/libpng.git"

config/software/gitlab-rails.rb

@@ -53,7 +53,6 @@
 dependency 'krb5'
 dependency 'registry'
 dependency 'unzip'
-dependency 'libre2'
 dependency 'gpgme'
 dependency 'graphicsmagick'
 dependency 'exiftool'
@@ -114,12 +113,6 @@
   bundle "config set --local gemfile #{gitlab_bundle_gemfile}" if gitlab_bundle_gemfile != 'Gemfile'
   bundle 'config force_ruby_platform true', env: env if OhaiHelper.ruby_native_gems_unsupported?
 
-  # This works around an issue with the grpc gem attempting to include
-  # /opt/gitlab/include headers instead of the vendored re2 headers:
-  # https://github.com/grpc/grpc/pull/32580. This can be removed
-  # after grpc is updated with that pull request.
-  env['CPPFLAGS'] = "-Ithird_party/re2 #{env['CPPFLAGS']}" if OhaiHelper.arm?
-
   bundle 'config build.gpgme --use-system-libraries', env: env
   bundle "config build.nokogiri --use-system-libraries --with-xml2-include=#{install_dir}/embedded/include/libxml2 --with-xslt-include=#{install_dir}/embedded/include/libxslt", env: env
   bundle 'config build.grpc --with-ldflags=-Wl,--no-as-needed --with-dldflags=-latomic', env: env if OhaiHelper.raspberry_pi?

config/software/libre2.rb

@@ -54,12 +54,6 @@
     shellout!("#{gem_bin} install --no-document gem-patch -v 0.1.6")
     shellout!("#{gem_bin} uninstall --force --all grpc")
 
-    # This works around an issue with the grpc gem attempting to include
-    # /opt/gitlab/include headers instead of the vendored re2 headers:
-    # https://github.com/grpc/grpc/pull/32580. This can be removed
-    # after grpc is updated with that pull request.
-    env['CPPFLAGS'] = "-Ithird_party/re2 #{env['CPPFLAGS']}"
-
     grpc_versions.each do |version|
       patch_path = patches[version]
       gemfile = "grpc-#{version}.gem"

config/software/ruby-grpc.rb

@@ -4,6 +4,5 @@
 
 <!-- Keep this list sorted alphabetically. -->
 - [golang](upgrade-golang-testplan.md)
-- [libre2](upgrade-libre2-testplan.md)
 - [Mattermost](upgrade-mattermost-testplan.md)
 - [redis](upgrade-redis-testplan.md)