Build and configure gitaly-ruby

Manually triggered a build in https://gitlab.com/gitlab-org/omnibus-gitlab/-/jobs/24681869

New build https://gitlab.com/gitlab-org/omnibus-gitlab/-/jobs/24695577

Now rugged fails to compile.

Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

current directory:
/opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/rugged-0.26.0/ext/rugged
/opt/gitlab/embedded/bin/ruby -r ./siteconf20170726-5702-j7bk6e.rb extconf.rb
--no-use-system-libraries
checking for gmake... no
checking for make... yes
checking for cmake... yes
checking for pkg-config... yes
-- cmake .. -DBUILD_CLAR=OFF -DTHREADSAFE=ON -DBUILD_SHARED_LIBS=OFF
-DCMAKE_C_FLAGS=-fPIC -DCMAKE_BUILD_TYPE=RelWithDebInfo
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers.  Check the mkmf.log file for more details.  You may
need configuration options.

Provided configuration options:
	--with-opt-dir
	--with-opt-include
	--without-opt-include=${opt-dir}/include
	--with-opt-lib
	--without-opt-lib=${opt-dir}/lib
	--with-make-prog
	--without-make-prog
	--srcdir=.
	--curdir
	--ruby=/opt/gitlab/embedded/bin/$(RUBY_BASE_NAME)
	--with-sha1dc
	--without-sha1dc
	--use-system-libraries
extconf.rb:21:in `sys': ERROR: 'cmake .. -DBUILD_CLAR=OFF -DTHREADSAFE=ON
-DBUILD_SHARED_LIBS=OFF -DCMAKE_C_FLAGS=-fPIC -DCMAKE_BUILD_TYPE=RelWithDebInfo 
' failed (RuntimeError)
	from extconf.rb:83:in `block (2 levels) in <main>'
	from extconf.rb:80:in `chdir'
	from extconf.rb:80:in `block in <main>'
	from extconf.rb:77:in `chdir'
	from extconf.rb:77:in `<main>'

To see why this extension failed to compile, please check the mkmf.log which can
be found here:

/opt/gitlab/embedded/lib/ruby/gems/2.3.0/extensions/x86_64-linux/2.3.0/rugged-0.26.0/mkmf.log

extconf failed, exit code 1

Gem files will remain installed in
/opt/gitlab/embedded/lib/ruby/gems/2.3.0/gems/rugged-0.26.0 for inspection.
Results logged to
/opt/gitlab/embedded/lib/ruby/gems/2.3.0/extensions/x86_64-linux/2.3.0/rugged-0.26.0/gem_make.out

An error occurred while installing rugged (0.26.0), and Bundler cannot continue.
Make sure that `gem install rugged -v '0.26.0'` succeeds before bundling.
Makefile:48: recipe for target 'build' failed
make[1]: Leaving directory '/var/cache/omnibus/src/gitaly'

Error:

    make[1]: *** [build] Error 5