Use npm@7

Author: novemberborn

.github/workflows/ci.yml

@@ -29,6 +29,8 @@ jobs:
       - uses: actions/setup-node@v2
         with:
           node-version: ${{ matrix.node-version }}
+      - name: Upgrade npm
+        run: npm install --global npm@7
       - run: npm ci --no-audit
       - run: npm run cover
       - uses: codecov/codecov-action@v1
@@ -49,6 +51,8 @@ jobs:
       - uses: actions/setup-node@v2
         with:
           node-version: ^12.20
+      - name: Upgrade npm
+        run: npm install --global npm@7
       - run: npm ci --no-audit
       - run: npm i typescript@${TS_VERSION}
         env:
@@ -67,7 +71,7 @@ jobs:
         with:
           node-version: ^12.20
       - name: Upgrade npm
-        run: if [[ "$(npm -v)" != "6.14.10" ]]; then npm install --global npm@6.14.10; fi
+        run: if [[ "$(npm -v)" != "7.5.2" ]]; then npm install --global npm@7.5.2; fi
       - run: npm ci --no-audit
       - name: Test package-lock for unexpected modifications
         run: |
@@ -89,6 +93,8 @@ jobs:
       - uses: actions/setup-node@v2
         with:
           node-version: ^12.20
+      - name: Upgrade npm
+        run: npm install --global npm@7
       - run: npm install --no-shrinkwrap --no-audit
       - run: npm run cover
 
@@ -102,5 +108,7 @@ jobs:
       - uses: actions/setup-node@v2
         with:
           node-version: ^12.20
+      - name: Upgrade npm
+        run: npm install --global npm@7
       - run: npm ci
       - run: npx xo