Use :lang<text> instead of skipping text code blocks

doc/Type/IO/Handle.pod6

@@ -40,7 +40,7 @@ cause C<X::IO::BinaryAndEncoding> exception to be thrown.
 The open mode defaults to non-exclusive, read only (same as specifying
 C<:r>) and can be controlled by a mix of the following arguments:
 
-=begin code :skip-test :allow< B R >
+=begin code :lang<text> :allow< B R >
 :r      same as specifying   :mode<ro>  same as specifying nothing
 
 :w      same as specifying   :mode<wo>, :create, :truncate
@@ -61,7 +61,7 @@ to implode, depending on a particular implementation.
 
 The mode details are:
 
-=begin code :skip-test :allow< B R >
+=begin code :lang<text> :allow< B R >
 :mode<ro>  means "read only"
 :mode<wo>  means "write only"
 :mode<rw>  means "read and write"