Add support for julia hooks

This patch adds 2nd class support for hooks using julia as the language.
pre-commit will install any dependencies defined in the hooks repo
`Project.toml` file, with support for `additional_dependencies` as well.
Julia doesn't (yet) have a way to install binaries/scripts so for julia
hooks the `entry` value is a (relative) path to a julia script within
the hooks repository. When executing a julia hook the (globally
installed) julia interpreter is prepended to the entry.

Example `.pre-commit-hooks.yaml`:

```yaml
- id: foo
  name: ...
  language: julia
  entry: bin/foo.jl --arg1
```

Example hooks repo: https://github.com/fredrikekre/runic-pre-commit/tree/fe/julia
Accompanying pre-commit.com PR: https://github.com/pre-commit/pre-commit.com/pull/998

Fixes #2689.

pre_commit/all_languages.py

@@ -10,6 +10,7 @@ from pre_commit.languages import dotnet
 from pre_commit.languages import fail
 from pre_commit.languages import golang
 from pre_commit.languages import haskell
+from pre_commit.languages import julia
 from pre_commit.languages import lua
 from pre_commit.languages import node
 from pre_commit.languages import perl
@@ -33,6 +34,7 @@ languages: dict[str, Language] = {
     'fail': fail,
     'golang': golang,
     'haskell': haskell,
+    'julia': julia,
     'lua': lua,
     'node': node,
     'perl': perl,