Bump supported Crystal version

shard.yml

@@ -19,6 +19,6 @@ dependencies:
     github: kemalcr/kemal
     version: ~> 0.26.0
 
-crystal: 0.31.0
+crystal: 0.31.1
 
 license: AGPLv3

src/invidious/helpers/handlers.cr

@@ -237,16 +237,3 @@ class HTTP::Client
     response
   end
 end
-
-struct Crystal::ThreadLocalValue(T)
-  @values = Hash(Thread, T).new
-
-  def get(&block : -> T)
-    th = Thread.current
-    if !@values[th]?
-      @values[th] = yield
-    else
-      @values[th]
-    end
-  end
-end