Surprisingly, it may be that they have permanently removed all packages related to the arm64 architecture (Raspberry Pi and other SBC) from the deb.tpo repository and will not include them again in the fix to this issue that is expected to arrive soon…
See this comment:
If they don’t solve it in conjunction, I will open another issue to address this big damage, which is that the most popular SBC architecture (Raspberry Pi) cannot be left without official support from the Tor project 