CI - disable tau midi on all platforms for mix test

We have no tests for MIDI yet and until we do there's no need to start the midi server (which currently causes issues with the CI tests)

Author: samaaron

.github/workflows/build.yml

@@ -183,21 +183,23 @@ jobs:
       run: mix test
       env:
         TAU_LOG_PATH: ${{github.workspace}}/tau_log.txt
+        TAU_DISABLE_MIDI: true
       if: matrix.os == 'windows-latest'
 
     - name: BEAM Tests (Linux)
       working-directory: ${{github.workspace}}/app/server/beam/tau
       run: mix test
-      if: matrix.os == 'ubuntu-latest'
       env:
         TAU_LOG_PATH: ${{github.workspace}}/tau_log.txt
         TAU_DISABLE_MIDI: true
+      if: matrix.os == 'ubuntu-latest'
 
     - name: BEAM Tests (macOS)
       working-directory: ${{github.workspace}}/app/server/beam/tau
       run: mix test
       env:
         TAU_LOG_PATH: ${{github.workspace}}/tau_log.txt
+        TAU_DISABLE_MIDI: true
       if: matrix.os == 'macos-latest'
 
     - name: Ruby Tests (Mac/Linux)