build: release on focal and jammy

this will build on both focal and jammy and release both binaries.

Signed-off-by: Michael McCracken <[email protected]>

.github/workflows/build.yaml

@@ -3,9 +3,13 @@ on:
   pull_request:
 name: build
 jobs:
+  os_matrix:
+    strategy:
+      matrix:
+        os: [ubuntu-20.04, ubuntu-22.04]
   build:
     name: build
-    runs-on: ubuntu-22.04
+    runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v3
       - name: Set up golang
@@ -62,6 +66,7 @@ jobs:
           go get -v ./...
           make
           cp atomfs ~/bin
+          cp atomfs atomfs-${{ matrix.os }}
       - name: test
         run: |
           export PATH=~/bin:$PATH
@@ -79,4 +84,4 @@ jobs:
         if: startsWith(github.ref, 'refs/tags/')
         with:
           files: |
-            atomfs
+            atomfs-${{ matrix.os }}