updated github actions workflow

.github/workflows/build.yml

@@ -19,7 +19,7 @@ jobs:
         run: |
           apt update && apt install -y curl
           curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y
-          echo "source $HOME/.cargo/env" >> $GITHUB_ENV
+          echo ". $HOME/.cargo/env" >> $GITHUB_ENV
         shell: bash
 
       - name: Install Git

.github/workflows/testing.yml

@@ -11,6 +11,8 @@ permissions:
 jobs:
   build:
     runs-on: ubuntu-latest
+    container:
+      image: ubuntu:22.04
 
     steps:
       - name: Install Rust