Attempt to fix emscripten build (#413)

Author: mcbarton

.github/workflows/deploy-pages.yml

@@ -158,14 +158,14 @@ jobs:
       run: |
         ./emsdk/emsdk activate ${{matrix.emsdk_ver}}
         source ./emsdk/emsdk_env.sh
+        export SYSROOT_PATH=$PWD/emsdk/upstream/emscripten/cache/sysroot
         micromamba activate CppInterOp-wasm  
         git clone https://github.com/compiler-research/xeus-cpp.git
         cd ./xeus-cpp
         mkdir build
         pushd build
         export CMAKE_PREFIX_PATH=${{ env.PREFIX }} 
         export CMAKE_SYSTEM_PREFIX_PATH=${{ env.PREFIX }} 
-        export SYSROOT_PATH=$PWD/emsdk/upstream/emscripten/cache/sysroot
         emcmake cmake \
           -DCMAKE_BUILD_TYPE=${{ env.BUILD_TYPE }}          \
           -DCMAKE_PREFIX_PATH=${{ env.PREFIX }}             \

.github/workflows/emscripten.yml

@@ -597,15 +597,15 @@ jobs:
       shell: bash -l {0}
       run: |
         ./emsdk/emsdk activate ${{matrix.emsdk_ver}}
-         source ./emsdk/emsdk_env.sh
+        source ./emsdk/emsdk_env.sh
+        export SYSROOT_PATH=$PWD/emsdk/upstream/emscripten/cache/sysroot
         micromamba activate CppInterOp-wasm  
         git clone https://github.com/compiler-research/xeus-cpp.git
         cd ./xeus-cpp
         mkdir build
         pushd build
         export CMAKE_PREFIX_PATH=${{ env.PREFIX }} 
         export CMAKE_SYSTEM_PREFIX_PATH=${{ env.PREFIX }} 
-        export SYSROOT_PATH=$PWD/emsdk/upstream/emscripten/cache/sysroot
         emcmake cmake \
           -DCMAKE_BUILD_TYPE=${{ env.BUILD_TYPE }}          \
           -DCMAKE_PREFIX_PATH=${{ env.PREFIX }}             \