update ubuntu build container (#93)

This PR is to update ubuntu build container to build `sbp2rinex`
compatible with more linux platforms (GLIBC).

Author: jackleckert

.github/workflows/ci.yaml

@@ -12,12 +12,19 @@ jobs:
     name: Run Checks and Build
     strategy:
       matrix:
-        os:
-        - windows-latest
-        - ubuntu-20.04
-        - macos-latest
+        include:
+          - os: windows-latest
+          - os: ubuntu-latest
+            container: ubuntu:20.04
+          - os: macos-latest
     runs-on: ${{ matrix.os }}
+    container: ${{ matrix.container }}
     steps:
+      - name: Install build dependencies (Ubuntu container)
+        if: matrix.container == 'ubuntu:20.04'
+        run: |
+          apt-get update && apt-get install -y build-essential git p7zip-full
+
       - name: Checkout source
         uses: actions/checkout@v4
         with:
@@ -69,7 +76,7 @@ jobs:
     needs:
       - build
     if: github.event_name == 'push' && contains(github.ref, 'refs/tags')
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
       - name: Store git tag and date vars.
         run: |