Bump base bound to 4.21 for GHC 9.12

Author: hasufell

filepath.cabal

@@ -91,7 +91,7 @@ library
 
   default-language: Haskell2010
   build-depends:
-    , base              >=4.12.0.0      && <4.21
+    , base              >=4.12.0.0      && <4.22
     , bytestring        >=0.11.3.0
     , deepseq
     , exceptions