build(deps): bump astral-sh/setup-uv from 5 to 6 (stac-utils#794)

* build(deps): bump astral-sh/setup-uv from 5 to 6

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]>

* ci: set activate-environment

---------

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

Author: dependabot[bot]

.github/workflows/continuous-integration.yml

@@ -26,7 +26,7 @@ jobs:
           - macos-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: astral-sh/setup-uv@v5
+      - uses: astral-sh/setup-uv@v6
         with:
           python-version: ${{ matrix.python-version }}
       - name: Sync
@@ -48,8 +48,9 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: astral-sh/setup-uv@v5
+      - uses: astral-sh/setup-uv@v6
         with:
+          activate-environment: true
           python-version: "3.10"
       - name: Install with min requirements
         run: uv sync --no-dev --resolution=lowest-direct
@@ -61,7 +62,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: astral-sh/setup-uv@v5
+      - uses: astral-sh/setup-uv@v6
       - name: Sync
         run: uv sync
       - name: Install any pre-releases of pystac
@@ -75,7 +76,7 @@ jobs:
     if: github.event_name != 'pull_request'
     steps:
       - uses: actions/checkout@v4
-      - uses: astral-sh/setup-uv@v5
+      - uses: astral-sh/setup-uv@v6
       - name: Sync
         run: uv sync
       - name: Install pystac from main
@@ -91,7 +92,7 @@ jobs:
         shell: bash -el {0}
     steps:
       - uses: actions/checkout@v4
-      - uses: astral-sh/setup-uv@v5
+      - uses: astral-sh/setup-uv@v6
       - name: Install pandoc
         run: sudo apt-get install -y pandoc
       - name: Sync