This provides "make sync-repos" to check out all locally available testsuites at
the commits indicated in their commit files, and "make sync-commits" to update
the commit files to the HEADs of the local testsuite repos.
Also adds the commit -> repo sync for the Makefile init target so initialization
always lands on the right version, and removes the corresponding explicit
checkout from the CI repo setup.
All changes in this patch were performed automatically with `shfmt` with
configuration flags specified in `.pre-commit-config.yaml`.
In addition to fixing whitespace the roundtrip through shfmt's AST also
transforms command substitutions
`cmd`
# becomes
$(cmd)
and some redirects
>&2 echo "msg"
# becomes
echo >&2 "msg"
The initialization of the private testsuite currently fails builds run in
forks. Cirrus's encrypted variables won't work outsize of the Zeek project, so
skip that setting altogether.