Update CI matrix: remove Ruby 3.0-3.2, add Ruby 4.0

Author: tobi

.github/workflows/liquid.yml

@@ -11,17 +11,15 @@ jobs:
     strategy:
       matrix:
         entry:
-          - { ruby: 3.0, allowed-failure: false } # minimum supported
-          - { ruby: 3.2, allowed-failure: false }
-          - { ruby: 3.3, allowed-failure: false }
-          - { ruby: 3.3, allowed-failure: false }
-          - { ruby: 3.4, allowed-failure: false } # latest
+          - { ruby: 3.3, allowed-failure: false } # minimum supported
+          - { ruby: 3.4, allowed-failure: false }
+          - { ruby: 4.0, allowed-failure: false } # latest
           - {
-              ruby: 3.4,
+              ruby: 4.0,
               allowed-failure: false,
               rubyopt: "--enable-frozen-string-literal",
             }
-          - { ruby: 3.4, allowed-failure: false, rubyopt: "--yjit" }
+          - { ruby: 4.0, allowed-failure: false, rubyopt: "--yjit" }
           - { ruby: head, allowed-failure: false }
           - {
               ruby: head,