Prepare release 9.4.6

configure.ac

docs/users_guide/9.4.6-notes.rst

docs/users_guide/release-notes.rst

libraries/base/base.cabal

libraries/base/changelog.md

libraries/ghc-prim/changelog.md

libraries/ghc-prim/ghc-prim.cabal

testsuite/tests/backpack/cabal/bkpcabal02/bkpcabal02.stdout

testsuite/tests/backpack/should_compile/bkp16.stderr

testsuite/tests/cabal/t18567/T18567.stderr

testsuite/tests/dependent/should_compile/T14729.stderr

testsuite/tests/dependent/should_compile/T15743.stderr

testsuite/tests/dependent/should_compile/T15743e.stderr

testsuite/tests/indexed-types/should_compile/T15711.stderr

testsuite/tests/indexed-types/should_compile/T15852.stderr

testsuite/tests/polykinds/T15592.stderr

testsuite/tests/polykinds/T15592b.stderr

testsuite/tests/printer/T18052a.stderr

testsuite/tests/rep-poly/RepPolyPatBind.stderr

testsuite/tests/th/T21547.stderr