ci: initial setup

Hope this works

.forgejo/workflows/rust.yaml

@@ -0,0 +1,29 @@
+name: Rust
+on: [push, workflow_dispatch]
+
+jobs:
+  build:
+    runs-on: poseidon-runner
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Install Rust
+      uses: msrd0/rust-toolchain@v1
+      with:
+        toolchain: stable
+
+    - name: install prerequisites
+      run: |
+        apt-get update
+        apt-get install -y curl build-essential gcc
+
+    - name: install rustfmt and rust-analyzer and nextest
+      run: |
+        rustup component add rustfmt
+        rustup component add rust-analyzer
+
+    - name: Run build
+      run: cargo build --locked --all-targets
+
+    - name: Run tests
+      run: cargo test