remove unnecessary prebuild steps in the GitHub workflow

Author: johnbartholomew

.github/workflows/build_and_test.yml

@@ -30,10 +30,6 @@ jobs:
     name: Build and test using plain Makefile
     runs-on: 'ubuntu-20.04'
     steps:
-      - name: Build environment setup
-        run: |
-          echo 'Nothing to do.'
-          echo 'GitHub runner includes tools we need already.'
       - uses: actions/checkout@v4
       - name: Build (make all)
         run: |
@@ -46,10 +42,6 @@ jobs:
     name: Build and test Python module
     runs-on: 'ubuntu-20.04'
     steps:
-      - name: Build environment setup
-        run: |
-          echo 'Nothing to do.'
-          echo 'GitHub runner includes tools we need already.'
       - uses: actions/checkout@v4
       - name: Build
         run: |
@@ -62,10 +54,6 @@ jobs:
     name: Build and test using CMake
     runs-on: 'ubuntu-20.04'
     steps:
-      - name: Build environment setup
-        run: |
-          echo 'Nothing to do.'
-          echo 'GitHub runner includes tools we need already.'
       - uses: actions/checkout@v4
       - name: Configure (cmake)
         run: |