Bump uv from 0.7.20 to 0.8.4 (#393)

* Bump uv from 0.7.20 to 0.8.4

Bumps [uv](https://github.com/astral-sh/uv) from 0.7.20 to 0.8.4.
- [Release notes](https://github.com/astral-sh/uv/releases)
- [Changelog](https://github.com/astral-sh/uv/blob/main/CHANGELOG.md)
- [Commits](astral-sh/uv@0.7.20...0.8.4)

---
updated-dependencies:
- dependency-name: uv
  dependency-version: 0.8.4
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

* Update test fixture for new output and exit code

* Add changelog entry

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Ed Morley <501702+edmorley@users.noreply.github.com>

Author: dependabot[bot]

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- Updated uv from 0.7.20 to 0.8.4. ([#393](https://github.com/heroku/buildpacks-python/pull/393))
+
 ## [2.2.3] - 2025-07-10
 
 ### Changed

requirements/uv.txt

@@ -1 +1 @@
-uv==0.7.20
+uv==0.8.4

tests/uv_test.rs

@@ -397,15 +397,15 @@ fn uv_lockfile_out_of_sync() {
                 Creating virtual environment
                 Running 'uv sync --locked --no-default-groups'
                 Resolved 2 packages in .+s
-                error: The lockfile at `uv.lock` needs to be updated, but `--locked` was provided. To update the lockfile, run `uv lock`.
+                The lockfile at `uv.lock` needs to be updated, but `--locked` was provided. To update the lockfile, run `uv lock`.
             "}
         );
         assert_contains!(
             context.pack_stderr,
             indoc! {"
                 [Error: Unable to install dependencies using uv]
                 The 'uv sync' command to install the app's
-                dependencies failed (exit status: 2).
+                dependencies failed (exit status: 1).
 
                 See the log output above for more information.
             "}