CI: add build workflow (thumbv6m-none-eabi check); remove dead traveo-hal dependency (upstream repo 404, blocked all dependency resolution)

.gitea/workflows/build.yml

@@ -0,0 +1,17 @@
+name: build
+on: [push, workflow_dispatch]
+
+jobs:
+  build-test:
+    runs-on: docker
+    container: rust:1-bookworm
+    timeout-minutes: 15
+    steps:
+      - name: Checkout
+        run: git clone --depth 1 ${{ github.server_url }}/${{ github.repository }}.git .
+
+      - name: Target (Cortex-M0)
+        run: rustup target add thumbv6m-none-eabi
+
+      - name: Check
+        run: cargo check --target thumbv6m-none-eabi