Zeekscript

* Add required version to pyproject.toml (Benjamin Bannier, Corelight)

* Drop unsupported macos-10.15 runner, add macos-12 (Benjamin Bannier, Corelight)

* Fix formatting of index slices (Benjamin Bannier, Corelight)

* Drop manually implemented test runner in favor of pytest. (Benjamin Bannier, Corelight)

* Use testutils-provided `zeekscript` import in tests (Benjamin Bannier, Corelight)

* Refactor tests to use common infrastructure (Christian Kreibich, Corelight)

* Start test cases for the zeekscript.Script class. (Christian Kreibich, Corelight)

* Support text and binary output in zeekscript.Script.write_tree(). (Christian Kreibich, Corelight)

* Avoid trailing whitespace in "zeek-script parse" output. (Christian Kreibich, Corelight)

* Fix black's code formatting that broke f-strings in parse tree output (Christian Kreibich, Corelight)

* Drop unsupported macos-10.15 runner, add macos-12 (Benjamin Bannier, Corelight)

* Remove pylint from CI requirements and README (Christian Kreibich and Benjamin Bannier, Corelight)

* Remove the existing pylint testcase, since pre-commit now covers pylint. (Christian Kreibich, Corelight)

* Run all pylint checkers for pre-commit hook (Benjamin Bannier, Corelight)

* Add pre-commit hook for running pylint (Benjamin Bannier, Corelight)

* Automatically upgrade Python sources with pyupgrade (Benjamin Bannier, Corelight)

* Add pre-commit hook for running pyupgrade (Benjamin Bannier, Corelight)

* Add GH action exercising pre-commit hooks (Benjamin Bannier, Corelight)

* Add `.git-blame-ignore-revs` (Benjamin Bannier, Corelight)

* Format Python sources with Black (Benjamin Bannier, Corelight)

* Fix race in project Makefile (Benjamin Bannier, Corelight)

The Makefile did not work correctly when used with `-jN` with `N>1`
since `test` did not declare its dependency on `build`.

This patch makes that dependency explicit, and also declares `build` as
PHONY so it is always run.

* Fix file selection of pre-commit hook (Benjamin Bannier, Corelight)

The `files` field expects a regexp, not a shell glob. We'd previously
select any file containing `zeek` in its name instead of files ending in
`.zeek`.

With this patch we use the intended selection.