Fix writing OPL tags to the problem file.

[drgrice1]

I change the name of the method that writes the tags of a WeBWorK::Utils::Tags object to its problem file from write to write_to_file in #3126. However, I didn't change the method name in place where this method was called in the WeBWorK::Utils::ListingDB package. As a result writing tags fails.

Note that the method name write does not pass the Subroutines::ProhibitBuiltinHomonyms policy. However, it only fails the policy with the caveat explicitly stated in their documentation which states "It is reasonable to declare an object method with the same name as a Perl built-in function, since they are easily distinguished from each other. However, at this time, Perl::Critic cannot tell whether a subroutine is static or an object method." This is one of my annoyances with that rule. It is generally a good rule, but it can't be implemented well. So the fix implemented here is to rename the method back to write, since it is a perfectly good object method name, and add ## no critic (Subroutines::ProhibitBuiltinHomonyms) to the line.