update set-output syntax

.github/workflows/build.yml

@@ -105,8 +105,8 @@ jobs:
             ARTIFACT_NAME="${{ matrix.board }}-zmk-ardux"
           fi
 
-          echo ::set-output name=shield-arg::${SHIELD_ARG}
-          echo ::set-output name=artifact-name::${ARTIFACT_NAME}
+          echo shield-arg=${SHIELD_ARG} >>$GITHUB_OUTPUT
+          echo artifact-name=${ARTIFACT_NAME} >>$GITHUB_OUTPUT
       - name: Build (west build)
         run: west build -s zmk/app -b ${{ matrix.board }} -- ${{ steps.variables.outputs.shield-arg }} -DZMK_CONFIG="${GITHUB_WORKSPACE}/config"
       - name: ARDUX implementation dtsi file
@@ -135,15 +135,15 @@ jobs:
     steps:
       - name: Get current date/time
         id: date
-        run: echo "::set-output name=date::$(date +'%Y%m%d-%H%M')"
+        run: echo "date=$(date +'%Y%m%d-%H%M')" >>$GITHUB_OUTPUT
       - name: Generate release text
         id: release_text
         run: >
-          echo "::set-output name=release_text::$(echo '<b>Precompiled firmware files for ARDUX</b><br><br>
+          echo "release_text=$(echo '<b>Precompiled firmware files for ARDUX</b><br><br>
           Download a firmware file by expanding "Assets", right clicking, and choosing "Save File As" or "Save Link As".
           <br>${{ github.event.inputs.releaseBody }}
           <br>Released on ${{ steps.date.outputs.date }}.
-          <br><br>${{ steps.docker_build.outputs.commits }}')"
+          <br><br>${{ steps.docker_build.outputs.commits }}')" >>$GITHUB_OUTPUT
       - name: Download build artifacts for release
         uses: actions/download-artifact@v4
         with: