ci: integrate dagger with woodpecker

The Woodpecker agent is now capable of running Dagger
pipelines.

.woodpecker/woodpecker.yml

@@ -1,19 +1,10 @@
+---
 pipeline:
-  test:
-    image: golang:1.20.4
-    environment:
-    - GO_TEST_VERBOSE=1
-    - GO_TEST_COVER=1
+  dagger:
+    image: golang:1.20.4-alpine
     commands:
+    - apk add docker-cli
     - cd internal/build
-    - go run magefiles/main.go -v test
-    when:
-      event: pull_request
-
-  lint:
-    image: golangci/golangci-lint:v1.52.2-alpine
-    commands:
-    - cd internal/build
-    - go run magefiles/main.go -v lint
-    when:
-      event: pull_request
+    - go run .
+    volumes:
+    - /var/run/docker.sock:/var/run/docker.sock