feat: migrate from woodpecker to forgejo actions

.forgejo/workflows/firmware.yml

@@ -0,0 +1,18 @@
+---
+
+on: push
+
+jobs:
+
+  firmware:
+    runs-on: docker
+    steps:
+      - uses: https://code.forgejo.org/actions/checkout@v4
+      - name: prepare environment
+        run: |
+          apt update; apt install --yes python3-pip
+          pip3 install platformio
+      - name: build firmware image
+        run: |
+          cd esp
+          pio run

.woodpecker.yml

@@ -1,8 +0,0 @@
----
-pipeline:
-
-  firmware:
-    image: shaguarger/platformio@sha256:957b051ef5de99efc9a65d4444c5adeeb2fdda7d1b60fe747b6a7feb7ab368ee
-    commands:
-      - cd esp
-      - pio run