docker(deps): bump astral-sh/uv

Bumps [astral-sh/uv](https://github.com/astral-sh/uv) from 0.12.5-python3.14-trixie-slim to 0.12.8-python3.14-trixie-slim.
- [Release notes](https://github.com/astral-sh/uv/releases)
- [Changelog](https://github.com/astral-sh/uv/blob/main/CHANGELOG.md)
- [Commits](https://github.com/astral-sh/uv/compare/0.12.5...0.12.8)

---
updated-dependencies:
- dependency-name: astral-sh/uv
  dependency-version: 0.12.8-python3.14-trixie-slim
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Dockerfile

@@ -30,7 +30,7 @@ RUN set -eux \
 # Purpose: Installs s6-overlay and rootfs
 # Comments:
 #  - Don't leave anything extra in here either
-FROM ghcr.io/astral-sh/uv:0.12.5-python3.14-trixie-slim AS s6-overlay-base
+FROM ghcr.io/astral-sh/uv:0.12.8-python3.14-trixie-slim AS s6-overlay-base
 
 WORKDIR /usr/src/s6