chore(deps): update pre-commit hook adamchainz/django-upgrade to v1.20.0 (#3057)

[![Mend
Renovate](https://app.renovatebot.com/images/banner.svg)](https://renovatebot.com)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
|
[adamchainz/django-upgrade](https://togithub.com/adamchainz/django-upgrade)
| repository | minor | `1.19.0` -> `1.20.0` |

Note: The `pre-commit` manager in Renovate is not supported by the
`pre-commit` maintainers or community. Please do not report any problems
there, instead [create a Discussion in the Renovate
repository](https://togithub.com/renovatebot/renovate/discussions/new)
if you have any questions.

---

### Release Notes

<details>
<summary>adamchainz/django-upgrade (adamchainz/django-upgrade)</summary>

###
[`v1.20.0`](https://togithub.com/adamchainz/django-upgrade/blob/HEAD/CHANGELOG.rst#1200-2024-07-19)

[Compare
Source](https://togithub.com/adamchainz/django-upgrade/compare/1.19.0...1.20.0)

- Fix the `admin_register` fixer to avoid rewriting when there are
duplicate `ModelAdmin` classes in the file.

`Issue #&#8203;471
<https://github.com/adamchainz/django-upgrade/issues/471>`\__.

</details>

---

### Configuration

📅 **Schedule**: Branch creation - At any time (no schedule defined),
Automerge - At any time (no schedule defined).

🚦 **Automerge**: Enabled.

♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the
rebase/retry checkbox.

🔕 **Ignore**: Close this PR and you won't be reminded about this update
again.

---

- [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check
this box

---

This PR has been generated by [Mend
Renovate](https://www.mend.io/free-developer-tools/renovate/). View
repository job log
[here](https://developer.mend.io/github/libretime/libretime).

<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiIzNy40MzEuNCIsInVwZGF0ZWRJblZlciI6IjM3LjQzMS40IiwidGFyZ2V0QnJhbmNoIjoibWFpbiIsImxhYmVscyI6WyJkZXBlbmRlbmNpZXMiXX0=-->

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

.pre-commit-config.yaml

@@ -42,7 +42,7 @@ repos:
         args: [--py38-plus]
 
   - repo: https://github.com/adamchainz/django-upgrade
-    rev: 1.19.0
+    rev: 1.20.0
     hooks:
       - id: django-upgrade
         args: [--target-version, "4.2"]