Run actions with Node 22

The github actions were previously ran with Node 20, this bumps them to Node 22.

README was also updated to reflect currently used version of Node.

.github/workflows/unit-tests.yml

@@ -19,10 +19,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4
-    - name: Use Node.js 20
+    - name: Use Node.js 22
       uses: actions/setup-node@v4
       with:
-        node-version: 20
+        node-version: 22
         cache: 'npm'
     - name: Install dependencies
       run: npm ci
@@ -40,10 +40,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4
-    - name: Use Node.js 20
+    - name: Use Node.js 22
       uses: actions/setup-node@v4
       with:
-        node-version: 20
+        node-version: 22
         cache: 'npm'
     - name: Install dependencies
       run: npm ci