Remove old PIO target from CI

.github/workflows/pio.yml

@@ -41,10 +41,3 @@ jobs:
       run: |
         pio run -d ./firmware \
           -e view \
-
-    - name: Build Firmware (handheld_tdisplay)
-      # Run regardless of other build step failures, as long as setup steps completed
-      if: always() && steps.pio_install.outcome == 'success'
-      run: |
-        pio run -d ./firmware \
-          -e handheld_tdisplay \