add unphone (#3584)

.github/workflows/main_matrix.yml

@@ -100,6 +100,7 @@ jobs:
           - board: t-deck
           - board: picomputer-s3
           - board: station-g2
+          - board: unphone
     uses: ./.github/workflows/build_esp32_s3.yml
     with:
       board: ${{ matrix.board }}