tests/input-types: split out scminputs into individual tests

This makes the test faster (by removing it and replacing it with a
`TestScmInput` module that exports the `testScmInput` subroutine). Now,
all the input tests can be run in parallel.

Some of the `tests/jobs/*-update.sh` scripts were "broken" (e.g. tests
failed for various reasons on my machine), so I fixed those up as well.

Co-authored-by: gustavderdrache <gustavderdrache@gmail.com>

tests/jobs/git-update.sh

@@ -4,6 +4,7 @@ set -e
 
 repo=git-repo
 export HOME=$(pwd)
+export XDG_CONFIG_HOME=$(pwd)/.config
 STATE_FILE=$(pwd)/.git-state
 if test -e $STATE_FILE; then
     state=$(cat $STATE_FILE)