bash: Deprecate unnecessary withDocs flag

Bash is distributing the rendered docs with the source,
so no build tools are used or needed anymore.

This was not the case originally, see dd91141a06

pkgs/shells/bash/5.nix

@@ -9,8 +9,7 @@
   # patch for cygwin requires readline support
 , interactive ? stdenv.hostPlatform.isCygwin
 , readline
-, withDocs ? false
-, texinfo
+, withDocs ? null
 , forFHSEnv ? false
 
 , pkgsStatic
@@ -22,6 +21,9 @@ let
     inherit sha256;
   });
 in
+lib.warnIf (withDocs != null) ''
+  bash: `.override { withDocs = true; }` is deprecated, the docs are always included.
+''
 stdenv.mkDerivation rec {
   pname = "bash${lib.optionalString interactive "-interactive"}";
   version = "5.2${patch_suffix}";
@@ -101,7 +103,6 @@ stdenv.mkDerivation rec {
   # Note: Bison is needed because the patches above modify parse.y.
   depsBuildBuild = [ buildPackages.stdenv.cc ];
   nativeBuildInputs = [ updateAutotoolsGnuConfigScriptsHook bison ]
-    ++ lib.optional withDocs texinfo
     ++ lib.optional stdenv.hostPlatform.isDarwin stdenv.cc.bintools;
 
   buildInputs = lib.optional interactive readline;

pkgs/top-level/all-packages.nix

@@ -5592,11 +5592,9 @@ with pkgs;
   # WARNING: this attribute is used by nix-shell so it shouldn't be removed/renamed
   bashInteractive = callPackage ../shells/bash/5.nix {
     interactive = true;
-    withDocs = true;
   };
   bashInteractiveFHS = callPackage ../shells/bash/5.nix {
     interactive = true;
-    withDocs = true;
     forFHSEnv = true;
   };