Fix FTBFS: remove rubygem-eventmachine build dependnecy

as it's only used in tests, and was removed from the distribution.

Resolves: rhbz#1982404

rubygem-mysql2.spec

@@ -6,7 +6,7 @@
 
 Name: rubygem-%{gem_name}
 Version: 0.5.3
-Release: 8%{?dist}
+Release: 9%{?dist}
 Summary: A simple, fast Mysql library for Ruby, binding to libmysql
 License: MIT
 URL: https://github.com/brianmario/mysql2
@@ -28,8 +28,6 @@ BuildRequires: rubygem(rspec)
 # Used in mysql_install_db
 BuildRequires: %{_bindir}/hostname
 BuildRequires: rubygem(bigdecimal)
-# Used in spec/em/em_spec.rb
-BuildRequires: rubygem(eventmachine)
 %endif
 
 %description
@@ -180,6 +178,10 @@ kill "$(cat "${MYSQL_TEST_PID_FILE}")"
 
 
 %changelog
+* Fri Jul 16 2021 Pavel Valena <pvalena@redhat.com> - 0.5.3-9
+- Fix FTBFS: remove rubygem-eventmachine dependnecy
+  Resolves: rhbz#1982404
+
 * Fri Apr 16 2021 Mohan Boddu <mboddu@redhat.com> - 0.5.3-8
 - Rebuilt for RHEL 9 BETA on Apr 15th 2021. Related: rhbz#1947937