Prepare an unexpected 2.23.1 release

Unfortunately, the 2.23.0 release is broken on 8.8.2 and 8.8.3. However,
there is no good backwards compatible fix. The fix going forward is:

  - Revise already release `haddock-api-2.23.0` to build only on
    `ghc-8.8.1` (this is the truth - it won't build on 8.8.2 or 8.8.3)

  - Release `haddock-api-2.23.1` and `haddock-2.23.1` to build only on
    `ghc-8.8.2` and `ghc-8.8.3`

Given that there are hardly any commits between these two releases, and
this is mostly one (not user visible) backwards incompatible change,
the changelog won't be updated.

haddock-api/haddock-api.cabal

 cabal-version:        2.0
 name:                 haddock-api
-version:              2.23.0
+version:              2.23.1
 synopsis:             A documentation-generation tool for Haskell libraries
 description:          Haddock is a documentation-generation tool for Haskell
                       libraries
@@ -43,7 +43,7 @@ library
 
   -- this package typically supports only single major versions
   build-depends: base            ^>= 4.13.0
-               , ghc             ^>= 8.8
+               , ghc             ^>= 8.8 && >= 8.8.2
                , ghc-paths       ^>= 0.1.0.9
                , haddock-library ^>= 1.8.0
                , xhtml           ^>= 3000.2.2
@@ -165,7 +165,7 @@ test-suite spec
     Haddock.Backends.Hyperlinker.Parser
     Haddock.Backends.Hyperlinker.Types
 
-  build-depends: ghc             ^>= 8.8
+  build-depends: ghc             ^>= 8.8 && >= 8.8.2
                , ghc-paths       ^>= 0.1.0.12
                , haddock-library ^>= 1.8.0
                , xhtml           ^>= 3000.2.2

haddock.cabal

 cabal-version:        2.4
 name:                 haddock
-version:              2.23.0
+version:              2.23.1
 synopsis:             A documentation-generation tool for Haskell libraries
 description:
   This is Haddock, a tool for automatically generating documentation
@@ -33,7 +33,7 @@ bug-reports:          https://github.com/haskell/haddock/issues
 copyright:            (c) Simon Marlow, David Waern
 category:             Documentation
 build-type:           Simple
-tested-with:          GHC==8.8.*
+tested-with:          GHC==8.8.2
 
 extra-source-files:
   CHANGES.md
@@ -142,7 +142,7 @@ executable haddock
   else
     -- in order for haddock's advertised version number to have proper meaning,
     -- we pin down to a single haddock-api version.
-    build-depends:  haddock-api == 2.23.0
+    build-depends:  haddock-api == 2.23.1
 
 test-suite html-test
   type:             exitcode-stdio-1.0