Add Ruby 3.4 to Mastodon 4.3 test matrix (#34028)

.github/actions/setup-ruby/action.yml

@@ -21,3 +21,4 @@ runs:
       with:
         ruby-version: ${{ inputs.ruby-version }}
         bundler-cache: true
+        cache-version: 4.3

.github/workflows/test-ruby.yml

@@ -127,6 +127,7 @@ jobs:
           - '3.1'
           - '3.2'
           - '.ruby-version'
+          - '3.4'
     steps:
       - uses: actions/checkout@v4
 
@@ -229,6 +230,7 @@ jobs:
           - '3.1'
           - '3.2'
           - '.ruby-version'
+          - '3.4'
     steps:
       - uses: actions/checkout@v4
 
@@ -308,6 +310,7 @@ jobs:
           - '3.1'
           - '3.2'
           - '.ruby-version'
+          - '3.4'
 
     steps:
       - uses: actions/checkout@v4
@@ -425,6 +428,7 @@ jobs:
           - '3.1'
           - '3.2'
           - '.ruby-version'
+          - '3.4'
         search-image:
           - docker.elastic.co/elasticsearch/elasticsearch:7.17.13
         include: