chore(deps): pin dependencies (#3)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| alpine | final | pinDigest |  -> `c5b1261` |
| koalaman/shellcheck-alpine |  | pinDigest |  -> `f73b035` |
| [pipelinecomponents/hadolint](https://gitlab.com/pipeline-components/hadolint) |  | pinDigest |  -> `430e949` |
| plugins/docker |  | pinDigest |  -> `2f15740` |

---

### 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.

👻 **Immortal**: This PR will be recreated if closed unmerged. Get [config help](https://github.com/renovatebot/renovate/discussions) if that's undesired.

---

 - [ ] <!-- 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:eyJjcmVhdGVkSW5WZXIiOiIzNy4xNTIuMSIsInVwZGF0ZWRJblZlciI6IjM3LjE1Mi4xIiwidGFyZ2V0QnJhbmNoIjoibWFzdGVyIn0=-->

Reviewed-on: mg/routeros-config-export#3
Co-authored-by: Renovate Bot <renovate@mgrote.net>
Co-committed-by: Renovate Bot <renovate@mgrote.net>

.woodpecker/build.yml

@@ -3,7 +3,7 @@ depends_on:
   - lint
 steps:
   selfhosted_tag:
-    image: plugins/docker
+    image: plugins/docker@sha256:2f157400c2cb7de1b309b0f044f119375108218e54d38e1340e00b9f93abdefb
     settings:
       dockerfile: Dockerfile
       repo: registry.mgrote.net/routeros-config-export
@@ -15,7 +15,7 @@ steps:
         - tag
 
   selfhosted_push:
-    image: plugins/docker
+    image: plugins/docker@sha256:2f157400c2cb7de1b309b0f044f119375108218e54d38e1340e00b9f93abdefb
     settings:
       dockerfile: Dockerfile
       repo: registry.mgrote.net/routeros-config-export

.woodpecker/lint.yml

@@ -10,7 +10,7 @@ steps:
           - tag
 
   hadolint:
-    image: pipelinecomponents/hadolint:0.25.9
+    image: pipelinecomponents/hadolint:0.25.9@sha256:430e949e6554d56ffc2dd08898ee609c71822d7fa1033f7c4dc240e90f2aac23
     commands:
       - hadolint Dockerfile
     when:
@@ -19,7 +19,7 @@ steps:
           - tag
 
   shellcheck:
-    image: koalaman/shellcheck-alpine:stable
+    image: koalaman/shellcheck-alpine:stable@sha256:f73b035c8ebfc8a66ba54e07af5cc41e790cf41fff45317914b1ce677dd9cada
     commands:
       - "find . -name *.sh -exec shellcheck {} +"
     when:

Dockerfile

@@ -1,4 +1,4 @@
-FROM alpine:3
+FROM alpine:3@sha256:c5b1261d6d3e43071626931fc004f70149baeba2c8ec672bd4f27761f8e1ad6b
 
 # hadolint ignore=DL3018
 RUN apk add --no-cache \