BNFC 2.9.6.1

• Haskell: restore LANGUAGE DeriveDataTypeable in generated Abs.hs; fixes regression in 2.9.6 [#507]

Builds with GHC versions:

• with cabal, GHC 8.0 - 9.12
• with stack, GHC 8.4 - 9.12

Linux64	bnfc-2.9.6.1-linux-x86_64.binary
Mac	bnfc-2.9.6.1-mac.pkg
Source	BNFC-2.9.6.1.tar.gz
Win	bnfc-2.9.6.1-win.exe