* Fixes to phar stub

There were a couple of issues with the phar stub. It seems that in the
past people did not realise they had to change shortarc.php and run
makestub.php to generate the stubfile and instead they modified stub.h
manually. This meant that there were a couple of mistakes in the stub
which are fixed in this patch. In particular:

* The title tag was not closed
* The length of the stub was wrong in stub.h
* This PR syncs previous changes to stub.h back to shortarc.php
  and vice versa.
* Adds a note such that hopefully no mistakes against updating the stubs
  are made in the future (hopefully).
* The makestub.php script was actually broken because the expected
  signature of the stub got changed in b874f1a

* Verify that the phar stub is up-to-date in CI

* Update stub again after master changes

* size_t changes

* Update test after stub changes (canonical casts)

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Co-authored-by: Joe Watkins <krakjoe@php.net>