Version 7.7-5 of gdb-avr is marked for autoremoval from testing on Mon 30 May 2022. It is affected by #1010451. You should try to prevent the removal by fixing these RC bugs.
Standards version of the package is outdated.
high
The package is severely out of date with respect to the Debian Policy.The package should be updated to follow the last version of Debian Policy
(Standards-Version 4.6.1 instead of
3.9.5).
The current maintainer is looking for someone who can take over
maintenance of this package. If you are interested in this
package, please consider taking it over. Alternatively you may
want to be co-maintainer in order to help the actual
maintainer. Please see bug number #969204 for more information.