Tweak CI cache (#2904)

Enable cache on Windows and fix cache directory to work on all OS'es

.github/workflows/ci.yml

@@ -36,11 +36,15 @@ jobs:
         with:
           node-version: ${{ matrix.node }}
 
+      - name: Get npm cache directory
+        id: npm-cache
+        run: |
+          echo "::set-output name=dir::$(npm config get cache)"
+
       - name: Set up npm cache
         uses: actions/cache@v2
-        if: ${{ !startsWith(runner.os, 'windows') }}
         with:
-          path: ~/.npm
+          path: ${{ steps.npm-cache.outputs.dir }}
           key: ${{ runner.os }}-node-v${{ env.node }}-${{ hashFiles('package.json') }}-${{ hashFiles('package-lock.json') }}}
           restore-keys: |
             ${{ runner.OS }}-node-v${{ env.node }}-${{ hashFiles('package.json') }}-${{ hashFiles('package-lock.json') }}

.github/workflows/docs.yml

@@ -34,10 +34,15 @@ jobs:
       - name: Disable gem docs
         run: 'echo "gem: --no-document" > ~/.gemrc'
 
+      - name: Get npm cache directory
+        id: npm-cache
+        run: |
+          echo "::set-output name=dir::$(npm config get cache)"
+
       - name: Set up npm cache
         uses: actions/cache@v2
         with:
-          path: ~/.npm
+          path: ${{ steps.npm-cache.outputs.dir }}
           key: ${{ runner.os }}-node-v${{ env.node }}-${{ hashFiles('package.json') }}-${{ hashFiles('package-lock.json') }}}
           restore-keys: |
             ${{ runner.OS }}-node-v${{ env.node }}-${{ hashFiles('package.json') }}-${{ hashFiles('package-lock.json') }}