Update dependency ruby from 3.2.3 to 3.3.0 (#48)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: Róbert Papp (TWiStErRob) <papp.robert.s@gmail.com>

.github/workflows/CI.yml

@@ -39,7 +39,7 @@ jobs:
         uses: ruby/setup-ruby@v1
         with:
           ruby-version: '2.7.8'
-          bundler-cache: true
+          bundler-cache: false
           cache-version: 0 # Increment this number if you need to re-download cached gems.
 
       - name: "Install fontcustom with all dependencies."
@@ -139,10 +139,11 @@ jobs:
           ref: ${{ steps.params.outputs.sha }}
 
       - name: "Setup old Ruby."
+        if: steps.cache.outputs.cache-hit != 'true'
         uses: ruby/setup-ruby@v1
         with:
           ruby-version: '2.7.8'
-          bundler-cache: true
+          bundler-cache: false
           cache-version: 0 # Increment this number if you need to re-download cached gems.
 
       - name: "Install fontcustom with all dependencies."

.ruby-version

@@ -1 +1 @@
-3.2.3
+3.3.0

Gemfile

@@ -3,7 +3,9 @@ source 'https://rubygems.org'
 # See https://github.com/TWiStErRob/twisterrob.github.io#upgrade
 # Current latest version: https://pages.github.com/versions/
 # For some reason omitting the version defaults to 0.
-gem 'github-pages', '= 228', group: :jekyll_plugins
+# TODO decouple, because it's unmaintained https://github.com/github/pages-gem/issues/890
+# Use specific ref, because last release was more than a year ago, master seems to have support for Ruby 3.3 and Jekyll 3.9.4.
+gem 'github-pages', :github => 'github/pages-gem', :ref => '974872fe73f8ec0b704e48f5c1f150df7a508e01', group: :jekyll_plugins
 
 # https://jekyllrb.com/docs/windows/#auto-regeneration
 # For --watch to work on Windows.