Correct `cabal` versioning

zcash-haskell.cabal

@@ -1,4 +1,4 @@
-cabal-version: 3.8
+cabal-version: 3.0
 
 -- This file has been generated from package.yaml by hpack version 0.36.0.
 --
@@ -57,7 +57,7 @@ library
     , text
   build-tool-depends:
     c2hs:c2hs
-  default-language: GHC2021
+  default-language: Haskell2010
 
 test-suite zcash-haskell-test
   type: exitcode-stdio-1.0
@@ -75,4 +75,4 @@ test-suite zcash-haskell-test
     , text
     , zcash-haskell
   pkgconfig-depends: rustzcash_wrapper
-  default-language: GHC2021
+  default-language: Haskell2012