Remove meta-tags.gemspec and Rakefile from the gem package

[kpumuk]

Bunlding gemspec does not make much sense since it is only used in development to produce metadata, added to the gem package as a YAML-serialized Gem::Specification. Additionally, Rakefile is also removed, as it is only used in development.

File list difference

To test, I built the gem with rake build and compared the listing before and after the change:

tar -xOzf pkg/meta-tags-2.22.0.gem data.tar.gz | tar -tzf -

Full diff:

--- before.txt	2024-09-13 20:39:38
+++ after.txt	2024-09-13 20:39:29
@@ -3,7 +3,6 @@
 CONTRIBUTING.md
 MIT-LICENSE
 README.md
-Rakefile
 certs/kpumuk.pem
 lib/generators/meta_tags/install_generator.rb
 lib/generators/meta_tags/templates/config/initializers/meta_tags.rb
@@ -19,7 +18,6 @@
 lib/meta_tags/text_normalizer.rb
 lib/meta_tags/version.rb
 lib/meta_tags/view_helper.rb
-meta-tags.gemspec
 sig/lib/_internal/rails.rbs
 sig/lib/meta_tags.rbs
 sig/lib/meta_tags/configuration.rbs