chore(ci): Use Woodpecker CI

.build.yml

@@ -1,14 +0,0 @@
-image: ubuntu/next
-packages:
-  - dpkg
-  - dpkg-dev
-  - scdoc
-  - shellcheck
-
-sources:
-  - https://git.sr.ht/~earnestma/aptpkg
-
-tasks:
-  - test: |
-      cd aptpkg
-      make test

.woodpecker.yml

@@ -0,0 +1,18 @@
+branches: main # Ideally, only run on pushes to main branch and PRs
+pipeline:
+  pull-request:
+    image: ubuntu:jammy
+    when:
+      event: [ pull_request ]
+    commands:
+      - apt install dpkg dpkg-dev scdoc shellcheck
+      - make test
+  
+  main:
+    image: ubuntu:jammy
+    when:
+      event: push
+      branch: main
+    commands:
+      - apt install dpkg dpkg-dev scdoc shellcheck
+      - make test