Tracking: PR's on hold until after 0.5.x migration

[martinflorian-da]

Context:

The major upgrade will be difficult for everyone involved, let's reduce the difficulty if the impact seems reasonable.

So: Anything that could cause problem should be delayed, if possible/reasonable, until one release after the one we HDM to (if we HDM to 0.5.0, then things can be merged in 0.5.1).

"Could cause problems" more specifically:

• potentially require config changes for operators, otherwise things break
• will cause topology changes on Canton
• changes some API that people use in some breaking way (which we shouldn't do anyway I guess?)
• might require a lengthy database migration
• might require a lengthy re-ingestion of things

Currently on hold for that reason:

• Rotate OTK keys with missing signatures #1912
• Improve authorization checks for CN app APIs #2509
• [wait until 0.5.1] Disable UpdateHistory for SV and Splitwell apps #2675
• Don't set expiration on auth tokens #3105