Bump pandoc version to 3.0.

In light of the package splitting changes.

pandoc-cli/pandoc-cli.cabal

@@ -57,7 +57,7 @@ executable pandoc
   hs-source-dirs:  src
   main-is:         pandoc.hs
   buildable:       True
-  build-depends:   pandoc >= 2.20,
+  build-depends:   pandoc >= 3.0,
                    hslua-cli >= 1.2 && < 1.3
   other-modules:   PandocCLI.Server
   if flag(server)

pandoc-server/pandoc-server.cabal

@@ -49,7 +49,7 @@ common common-executable
 
 library
   import:        common-options
-  build-depends: pandoc                >= 2.20,
+  build-depends: pandoc                >= 3.0,
                  pandoc-types          >= 1.22.2   && < 1.23,
                  containers            >= 0.6.0.1  && < 0.7,
                  aeson                 >= 2.0      && < 2.2,

pandoc.cabal

@@ -1,6 +1,6 @@
 cabal-version:   2.4
 name:            pandoc
-version:         2.20
+version:         3.0
 build-type:      Simple
 license:         GPL-2.0-or-later
 license-file:    COPYING.md