Generate `pre-commit` hook stages and `identify` tags with a locking rule.

The stages.bzl and tags.bzl have been generated by pulling the relevant data out of the pre-commit and identify packages.

Writing a rule that generates the .bzl files from the source data will allow each upgrading of the pre-commit version.

The rule would need to look something similar to:

# pre-commit/BUILD.bazel
load("//pre-commit/python/expand/template:rule.bzl", "pre_commit_python_expand_template")

pre_commit_python_expand_template(
    name = "stages",
    src = "stages.tmpl.bzl",
    substitutions = {
        "{{stages}}": "pre_commit.clientlib:STAGES",
    },
    out = "stages.bzl",
)

Doing bazelisk run -- pre-commit:stages would generate the pre-commit/stages.bzl file from the source data in pre_commit.clientlib:STAGES.

The same thing will be done for pre-commit/tags.bzl:

# pre-commit/BUILD.bazel
load("//pre-commit/python/expand/template:rule.bzl", "pre_commit_python_expand_template")

pre_commit_python_expand_template(
    name = "tags",
    src = "tags.tmpl.bzl",
    substitutions = {
        "{{tags}}": "identify.identify:TAGS",
    },
    out = "tags.bzl",
)

The pre_commit_config rule can be used as an example of how to implement a generation rule.

The pre-commit/__main__.py shows how to load a Python specification such as pre_commit.clientlib:STAGES.