Only recognise Pod for .pod files (#3863)

We uncomplicate matters by removing ".pod" from the Perl definition
entirely.

samples/Pod/Sample.pod

@@ -0,0 +1,10 @@
+use strict;
+use warnings;
+package DZT::Sample;
+
+sub return_arrayref_of_values_passed {
+  my $invocant = shift;
+  return \@_;
+}
+
+1;