tool-versions: update to node 18

Node 16 reaches end of life in about 6 months so we might as well
update to 18 now since it seems to be working.

.github/workflows/coverage.yml

@@ -12,7 +12,7 @@ jobs:
     steps:
     - uses: actions/setup-node@v3
       with:
-        node-version: '16.x'
+        node-version: '18.x'
     - uses: actions/checkout@v3
     - run: yarn install
     - run: yarn coverage

.github/workflows/release.yml

@@ -17,7 +17,7 @@ jobs:
         echo "REACT_APP_SUFFIX=-beta" >> $GITHUB_ENV
     - uses: actions/setup-node@v3
       with:
-        node-version: '16.x'
+        node-version: '18.x'
     - uses: actions/checkout@v3
     - run: yarn install
     - run: yarn coverage

.github/workflows/test-pull-request.yml

@@ -19,7 +19,7 @@ jobs:
     steps:
     - uses: actions/setup-node@v3
       with:
-        node-version: '16.x'
+        node-version: '18.x'
     - uses: actions/checkout@v3
     - run: yarn install
     - run: |