Bump astral-sh/setup-uv from 5 to 6 (#539)

Bumps [astral-sh/setup-uv](https://github.com/astral-sh/setup-uv) from 5 to 6.
- [Release notes](https://github.com/astral-sh/setup-uv/releases)
- [Commits](astral-sh/setup-uv@v5...v6)

---
updated-dependencies:
- dependency-name: astral-sh/setup-uv
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/docker-gdal.yml

@@ -49,7 +49,7 @@ jobs:
       - uses: actions/checkout@v4
 
       - name: Install uv
-        uses: astral-sh/setup-uv@v5
+        uses: astral-sh/setup-uv@v6
 
       - name: Create virtual environment
         # use uv to create a virtual environment, then add it to environment

.github/workflows/release.yml

@@ -273,7 +273,7 @@ jobs:
           allow-prereleases: true
 
       - name: Install uv
-        uses: astral-sh/setup-uv@v5
+        uses: astral-sh/setup-uv@v6
 
       - name: Create virtual environment (Linux / MacOS)
         # use uv to create a virtual environment, then add it to environment