ci: remove QEMU setup from build workflows (#290)

Builds run on native runners (ubuntu-24.04 for amd64,
ubuntu-24.04-arm for arm64), so QEMU emulation is unused.
Removes the setup-qemu-action step from both build workflows.

Author: chorrell

.github/workflows/dockerimage.yml

@@ -68,9 +68,6 @@ jobs:
           ccache -s
           cp node-v$LATEST_VERSION/out/Release/node node
 
-      - name: Set up QEMU
-        uses: docker/setup-qemu-action@ce360397dd3f832beb865e1373c09c0e9f86d70a # v4.0.0
-
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@d7f5e7f509e45cec5c76c4d5afdd7de93d0b3df5 # v4.1.0
 

.github/workflows/update-current-image.yml

@@ -109,9 +109,6 @@ jobs:
           ccache -s
           cp node-v$NODE_VERSION/out/Release/node node
 
-      - name: Set up QEMU
-        uses: docker/setup-qemu-action@ce360397dd3f832beb865e1373c09c0e9f86d70a # v4.0.0
-
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@d7f5e7f509e45cec5c76c4d5afdd7de93d0b3df5 # v4.1.0