perlPackages.IOTty: upgrade to 1.20

Drop the now-unneeded patch. It is not required anymore starting with
1735a78 (Make function checks more robust within shared libs,
2023-04-04), and with the patch a couple of tests fail.

pkgs/development/perl-modules/IO-Tty-fix-makefile.patch

@@ -1,13 +0,0 @@
-diff --git a/Makefile.PL b/Makefile.PL
-index eaf47e0..32766d7 100644
---- a/Makefile.PL
-+++ b/Makefile.PL
-@@ -146,7 +146,7 @@ extern "C"
- /* We use char because int might match the return type of a gcc2
-    builtin and then its argument prototype would still apply.  */
- char $f ();
--char (*f) ();
-+char f;
- 
- #ifdef F77_DUMMY_MAIN
- #  ifdef __cplusplus

pkgs/top-level/perl-packages.nix

@@ -17750,12 +17750,11 @@ with self;
 
   IOTty = buildPerlPackage {
     pname = "IO-Tty";
-    version = "1.17";
+    version = "1.20";
     src = fetchurl {
-      url = "mirror://cpan/authors/id/T/TO/TODDR/IO-Tty-1.17.tar.gz";
-      hash = "sha256-pfGoMCC8W13WwbVw9Ix1RuCo9/rBCgaHQLA5Ja2eFOg=";
+      url = "mirror://cpan/authors/id/T/TO/TODDR/IO-Tty-1.20.tar.gz";
+      hash = "sha256-sVMJ/IViOJMonLmyuI36ntHmkVa3XymThVOkW+bXMK8=";
     };
-    patches = [ ../development/perl-modules/IO-Tty-fix-makefile.patch ];
     doCheck = !stdenv.hostPlatform.isDarwin; # openpty fails in the sandbox
     meta = {
       description = "Low-level allocate a pseudo-Tty, import constants";