Don't use spaces for variable interpolation

.github/workflows/ci.yml

@@ -34,15 +34,15 @@ jobs:
         if: matrix.arch != 'amd64'
         run: docker run --rm --privileged multiarch/qemu-user-static --reset -p yes
       - name: Build bitcoind
-        run: docker build --build-arg ARCH=${{ matrix.arch }} --build-arg VERSION=${{ matrix.version }} -t bitcoind:v${{ matrix.version }}-${{ matrix.arch }} .
+        run: docker build --build-arg ARCH=${{matrix.arch}} --build-arg VERSION=${{matrix.version}} -t bitcoind:v${{matrix.version}}-${{matrix.arch}} .
       - name: Log image data
         run: docker images bitcoind
       - name: Log OS details
-        run: docker run --entrypoint sh bitcoind:v${{ matrix.version }}-${{ matrix.arch }} '-c' 'uname -a && . /etc/os-release && echo $PRETTY_NAME'
+        run: docker run --entrypoint sh bitcoind:v${{matrix.version}}-${{matrix.arch}} '-c' 'uname -a && . /etc/os-release && echo $PRETTY_NAME'
       - name: Check bitcoind -version
-        run: (docker run bitcoind:v${{ matrix.version }}-${{ matrix.arch }} -version | tee /dev/stderr | grep -q ${{ matrix.version }}) 2>&1
+        run: (docker run bitcoind:v${{matrix.version}}-${{matrix.arch}} -version | tee /dev/stderr | grep -q ${{matrix.version}}) 2>&1
       - name: Save image tarballs
-        run: mkdir -p images && docker save bitcoind:v${{ matrix.version }}-${{ matrix.arch }} | gzip > "images/bitcoind-v${{ matrix.version }}-${{ matrix.arch }}.tgz"
+        run: mkdir -p images && docker save bitcoind:v${{matrix.version}}-${{matrix.arch}} | gzip > "images/bitcoind-v${{matrix.version}}-${{matrix.arch}}.tgz"
       - name: Print sha256sum of built image
         run: sha256sum images/*
       - name: Upload image tarballs