perlPackages.MHonArc: remove merged patch

pkgs/development/perl-modules/mhonarc.patch

@@ -1,26 +0,0 @@
-diff --git a/lib/mhamain.pl b/lib/mhamain.pl
-index 80980a2..c1259ce 100644
---- a/lib/mhamain.pl
-+++ b/lib/mhamain.pl
-@@ -1562,7 +1562,7 @@ sub signal_catch {
- ##
- sub defineIndex2MsgId {
-     no warnings qw(deprecated);
--    if (!defined(%Index2MsgId)) {
-+    unless (%Index2MsgId) {
- 	foreach (keys %MsgId) {
- 	    $Index2MsgId{$MsgId{$_}} = $_;
- 	}
-diff --git a/lib/mhopt.pl b/lib/mhopt.pl
-index 02fb05e..939109b 100644
---- a/lib/mhopt.pl
-+++ b/lib/mhopt.pl
-@@ -865,7 +865,7 @@ sub update_data_1_to_2 {
- sub update_data_2_1_to_later {
-     no warnings qw(deprecated);
-     # we can preserve filter arguments
--    if (defined(%main::MIMEFiltersArgs)) {
-+    if (%main::MIMEFiltersArgs) {
- 	warn qq/         preserving MIMEARGS...\n/;
- 	%readmail::MIMEFiltersArgs = %main::MIMEFiltersArgs;
- 	$IsDefault{'MIMEARGS'} = 0;

pkgs/top-level/perl-packages.nix

@@ -15422,8 +15422,6 @@ with self; {
       hash = "sha256-RX3HN07lnLdaBynlHO8vLFK0gYD3Odj9lW6hmIKBXzM=";
     };
 
-    patches = [ ../development/perl-modules/mhonarc.patch ];
-
     outputs = [ "out" "dev" ]; # no "devdoc"
 
     installTargets = [ "install" ];