cabal: Loosen mtl bounds

Author: ali-abrar

postgresql-simple-interpolate.cabal

@@ -24,7 +24,7 @@ library
   build-depends:
     base >= 4.5 && < 5,
     haskell-src-meta >= 0.6 && < 0.9,
-    mtl >=2.1 && < 2.3,
+    mtl >=2.1 && < 2.4,
     parsec ==3.1.*,
     postgresql-simple >= 0.1,
     template-haskell
@@ -40,4 +40,3 @@ benchmark criterion
                  , template-haskell
     default-language:    Haskell2010
     type: exitcode-stdio-1.0
-