Allow tabs for container-based builds

* Gem versions follow GHA in foreman-documentation for PR 3104 that
  introduces tabs which require "asciidoctor-tabs".
* Install bundler as RPM.

Dockerfile

@@ -8,12 +8,17 @@ RUN dnf install -y \
         make \
         redhat-rpm-config \
         ruby-devel \
-        rubygem-asciidoctor && \
+        rubygem-asciidoctor \
+        rubygem-bundler && \
     dnf groupinstall -y development-tools && \
     gem install \
+        asciidoctor-tabs:1.0.0.beta.6 \
         ffi:1.16.3 \
-        nokogiri \
+        nokogiri:1.16.5 \
+        racc:1.8.0 \
+        rb-fsevent:0.11.2 \
         rb-inotify:0.10.1 \
-        sass
+        sass-listen:4.0.0 \
+        sass:3.7.4
 
 WORKDIR /foreman-documentation/guides