Use latest NodeJS on CI (#273)

The CI builds started failing on node `v22.5.0` likely due to
nodejs/node#53902

The NodeJS version on CI was therefore pinned to 21 in
#272

This pull request goes back to using the latest NodeJS version, and
should be merged to master once the issue with NodeJS `v22.5.0` noted
above is fixed, and the build on this pull request succeeds.

.github/workflows/main.yml

@@ -22,7 +22,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v4
         with:
-          node-version: '21'
+          node-version: 'latest'
           cache: 'yarn'
 
       - name: Install dependencies
@@ -39,7 +39,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v4
         with:
-          node-version: '21'
+          node-version: 'latest'
           cache: 'yarn'
 
       - name: Install dependencies