> This mini-PR gets rid of constants in functional tests that are not used anymore. Found by vulture via the following script that has been lying around here locally for quite some time (I think it was once proposed by practicalswift, but I don't remember the concrete topic/PR):
> ```
> #!/bin/sh
> for F in $(git ls-files -- "*.py"); do vulture "$F" | grep "unused variable"; done
> ```
I used the script to find a few more unused variables and remove them. But note that it show mostly false positives (most likely because the test framework is not using "standard" python coding practices), so it is not a reliable way of finding unused variables.
I left some unused variables that will be removed by upcoming backports.
I also left a couple of unused variables to seem to document missing test coverage:
- `BLOCKSIZE_TOO_LOW` in `abc_rpc_excessiveblock.py` is an CLI error message that cannot be triggered via RPC
- `RPC_FORK_PRIOR_FINALIZED_ERROR` in `abc-finalize-block.py` is an error message that still exists in `validation.cpp` but is not tested
The constant removed in abc-schnormultisig.py is just an unused copy-pasta from abc-schnorr.py
This is a backport of core#20023