chore(deps): update actions/checkout action to v6 (#27)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [actions/checkout](https://github.com/actions/checkout) | action | major | `v5` -> `v6` |

---

### Release Notes

<details>
<summary>actions/checkout (actions/checkout)</summary>

### [`v6`](https://github.com/actions/checkout/blob/HEAD/CHANGELOG.md#v600)

[Compare Source](https://github.com/actions/checkout/compare/v5...v6)

- Persist creds to a separate file by [@&#8203;ericsciple](https://github.com/ericsciple) in [#&#8203;2286](https://github.com/actions/checkout/pull/2286)
- Update README to include Node.js 24 support details and requirements by [@&#8203;salmanmkc](https://github.com/salmanmkc) in [#&#8203;2248](https://github.com/actions/checkout/pull/2248)

</details>

---

### Configuration

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

🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied.

♻ **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 [Renovate Bot](https://github.com/renovatebot/renovate).
<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiI0Mi4xMC41IiwidXBkYXRlZEluVmVyIjoiNDIuMjYuMTEiLCJ0YXJnZXRCcmFuY2giOiJtYWluIiwibGFiZWxzIjpbImFjdGlvbiIsImRlcHMiXX0=-->

Reviewed-on: #27
Reviewed-by: t.behrendt <t.behrendt@noreply.localhost>
Co-authored-by: Renovate Bot <renovate@t00n.de>
Co-committed-by: Renovate Bot <renovate@t00n.de>

.gitea/workflows/cd.yaml

@@ -16,7 +16,7 @@ jobs:
       changes: ${{ steps.filter.outputs.code }}
     steps:
       - name: Checkout
-        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
 
       - name: Get changed files
         id: filter
@@ -42,8 +42,8 @@ jobs:
       - ubuntu-latest
       - linux_${{ matrix.arch }}
     steps:
-      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
-      - uses: docker/setup-buildx-action@e468171a9de216ec08956ac3ada2f0791b6bd435 # v3
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
+      - uses: docker/setup-buildx-action@8d2750c68a42422c14e847fe6c8ac0403b4cbd6f # v3
       - uses: docker/login-action@5e57cd118135c172c3672efd75eb46360885c0ef # v3
         with:
           registry: ${{ env.DOCKER_REGISTRY }}
@@ -72,7 +72,7 @@ jobs:
     outputs:
       tag: ${{ steps.tag.outputs.new-tag }}
     steps:
-      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
         with:
           fetch-depth: 0
       - uses: https://gitea.t000-n.de/t.behrendt/conventional-semantic-git-tag-increment@0.0.2
@@ -93,7 +93,7 @@ jobs:
       - create_tag
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
       - id: meta
         run: |
           echo REPO_NAME=$(echo ${GITHUB_REPOSITORY} | awk -F"/" '{print $2}' | tr '[:upper:]' '[:lower:]') >> $GITHUB_OUTPUT

.gitea/workflows/ci.yaml

@@ -10,8 +10,8 @@ jobs:
       - ubuntu-latest
       - linux_amd64
     steps:
-      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
-      - uses: docker/setup-buildx-action@e468171a9de216ec08956ac3ada2f0791b6bd435 # v3
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
+      - uses: docker/setup-buildx-action@8d2750c68a42422c14e847fe6c8ac0403b4cbd6f # v3
       - name: Build image
         uses: docker/build-push-action@263435318d21b8e681c14492fe198d362a7d2c83 # v6
         with:
@@ -27,7 +27,7 @@ jobs:
     name: Check syntax
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
       - name: Check syntax
         run: |
           bash -n src/backup.sh

Dockerfile

@@ -1,11 +1,15 @@
-FROM alpine:3.22@sha256:4b7ce07002c69e8f3d704a9c5d6fd3053be500b7f1c69fc0d80990c2ad8dd412
+FROM docker.io/alpine:3.23@sha256:51183f2cfa6320055da30872f211093f9ff1d3cf06f39a0bdb212314c5dc7375 AS base
+
+# Add edge repository for postgresql18-client
+RUN echo '@edge http://dl-cdn.alpinelinux.org/alpine/edge/main' >> /etc/apk/repositories
 
 RUN apk update && apk add --no-cache \
     bash \
     curl \
     restic \
-    postgresql-client \
-    jq
+    jq \
+    postgresql18-client@edge \
+    libpq@edge
 
 WORKDIR /app