deps: test on node@16.13.0, use npm@9 (#38)

- deps: require `node@^16.13.0`, test on `node@16.13.0`
  - this's the ver currently used when running js gh actions
- deps: require `npm@~9.20.0`
  - `npm@9.20.0` is compatible with `node@16.13.0`

.github/workflows/format-and-docs.yml

@@ -10,8 +10,6 @@ jobs:
   format:
     if: github.event_name != 'push' || !github.event.deleted
     runs-on: ubuntu-latest
-    env:
-      npm_config_engine_strict: true
     steps:
     # NOTE: Be mindful of what gets checked-out for pr events!
     - uses: actions/checkout@v3
@@ -21,6 +19,7 @@ jobs:
         node-version-file: package.json
         check-latest: true
 
+    - run: npm i -g "npm@$(npm pkg get engines.npm | grep -Eom 1 '[^"]+')"
     - run: npm ci
     - run: npm run format
 
@@ -65,8 +64,6 @@ jobs:
     needs: format
     if: github.event_name != 'push' || !github.event.deleted
     runs-on: ubuntu-latest
-    env:
-      npm_config_engine_strict: true
     steps:
     - uses: actions/checkout@v3
 
@@ -75,6 +72,7 @@ jobs:
         node-version-file: package.json
         check-latest: true
 
+    - run: npm i -g "npm@$(npm pkg get engines.npm | grep -Eom 1 '[^"]+')"
     - run: npm ci
     - run: npm run build-docs
 

.github/workflows/test.yml

@@ -13,9 +13,9 @@ jobs:
     - uses: actions/checkout@v3
     - uses: actions/setup-node@v3
       with:
-        # All gh runners have at least this version of node16 preinstalled
-        node-version: 16.18.0
-    - run: npm ci
+        node-version: 16.13.0
+    - run: npm i -g "npm@$(npm pkg get engines.npm | grep -Eom 1 '[^"]+')"
+    - run: npm ci --engine-strict=false
     - run: npm run build --if-present
     - run: npm test
       env: