chore(deps): update renovate/renovate docker tag to v39 (#3)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [renovate/renovate](https://renovatebot.com) ([source](https://github.com/renovatebot/renovate)) | major | `37` -> `39` |

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### 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.

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 - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box

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This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).
<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiIzNy40NDAuNyIsInVwZGF0ZWRJblZlciI6IjM3LjQ0MC43IiwidGFyZ2V0QnJhbmNoIjoibWFpbiIsImxhYmVscyI6WyJyZW5vdmF0ZSJdfQ==-->

Reviewed-on: #3
Co-authored-by: renovate-bot <renovate@ocram85.com>
Co-committed-by: renovate-bot <renovate@ocram85.com>

.woodpecker/lint.yml

@@ -12,7 +12,7 @@ matrix:
 
 steps:
   lint:
-    image: renovate/renovate:37
+    image: renovate/renovate:39
     pull: true
     commands:
       - renovate-config-validator

.woodpecker/renovate.yml

@@ -9,7 +9,7 @@ depends_on:
 
 steps:
   renovate-dry:
-    image: renovate/renovate:37
+    image: renovate/renovate:39
     secrets: [renovate_token, github_com_token]
     pull: true
     environment:
@@ -20,7 +20,7 @@ steps:
       - event: push
 
   renovate:
-    image: renovate/renovate:37
+    image: renovate/renovate:39
     secrets: [renovate_token, github_com_token]
     pull: true
     environment: