* Add `pre-commit` tool to dev-env
* Add pre-commit configuration
Fixes#15522
* Install pre-commit hooks inside the nix shell
* Limit buildifier hook to files to be comitted
The `:buildifier-fix` tool always runs on all Bazel files (by calling `find`),
which is not useful when using pre-commit.
* Install pre-commit hook only when `DADE_NO_PRE_COMMIT` is unset
Since direnv does not execute the shellHook, install in `.envrc` too.
* Introduce shell.nix to expose the Nix tooling, if required.
* dev-env: Rewrite the ghcide script to use nix-shell.
* language-support/hs: Use `nix-shell` for export-package.sh.
* Nix: Add a shebang to the Bazel wrapper script.
CHANGELOG_BEGIN
CHANGELOG_END
* dev-env: Standardize the `set` header in `ghcide`.