Spiir compatibility fixes

This Merge Request targets a 'review' branch I've created at the commit hash where SPIIR's changes are forked from: https://git.ligo.org/lscsoft/gstlal/-/tags/o4b-online-v1.0.0, which I believe is the reviewed O4b GstLAL online review tag.

The source branch, spiir_compatibility_fixes, is at the commit hash we intend to use in production. If any additional changes are needed, we can either add them to this branch, or review them separately.

You can see a list of the changes made by SPIIR here: https://docs.google.com/spreadsheets/d/1lQJzSIE6iUhlRQ5O4gjHBnIpsqFS7w3DQw3wX5_66P8/edit