python3-trio: Fixes Bug#13076 - allows fuse mount to work again

python3-trio: Fixes Bug#13076 - allows fuse mount to work again

- In Core 173 python3-trio was updated to version 0.22.0 when python was upgraded to 3.10.8
   Although the build of python3-trio was successful it was missed that there was a new
   run-time dependency of python3-exceptiongroup for python3-pyfuse3 to work.
   python2-flit_scm is required as a build dependency for python3-exceptiongroup.
- The modified packages were installed in my vm testbed and confirmed that borg mount then
   worked again.
- It was also noted that python3-attr was no longer needed neither as a runtime
   dependency nor as a build time dependency.
- Dependencies line of python3-trio updated for these two changes.

Fixes: Bug#13076
Tested-by: Adolf Belka <adolf.belka@ipfire.org>
Signed-off-by: Adolf Belka <adolf.belka@ipfire.org>