Version of a dependency Mail::DKIM::ARC::Signer to 0.55 due to bug fix.

See https://rt.cpan.org/Public/Bug/Display.html?id=129066

cpanfile

@@ -258,7 +258,7 @@ feature 'Mail::DKIM::Verifier', 'Required in order to use DKIM features (both fo
 };
 
 feature 'Mail::DKIM::ARC::Signer', 'Required in order to use ARC features to add ARC seals.' => sub {
-    requires 'Mail::DKIM::ARC::Signer', '>= 0.51';
+    requires 'Mail::DKIM::ARC::Signer', '>= 0.55';
 };
 
 feature 'Net::DNS', 'This is required if you set a value for "dmarc_protection_mode" which requires DNS verification.' => sub {