BUG: update url used to grab tag information

[tangkong]

Closes #351

Simply changes the url used to get package tag information. The old one seems to have died.

Tested by running this function on slac-alarm-manager (the failing case) and happi (the case I trusted to be working)

In [1]: from scripts.update_tags import pypi_latest_version_no_search

In [2]: pypi_latest_version_no_search("happi")
Out[2]: '2.6.0'

In [3]: pypi_latest_version_no_search("slac-alarm-manager")
Out[3]: '1.3.0'

[tangkong]

I found some docs: https://packaging.python.org/en/latest/specifications/simple-repository-api/

[ZLLentz]

Confirmed working via comparing the CI (it fails later now)
Thank you for noticing, diagnosing, and fixing. I noticed but didn't look any closer.