chore(deps): update actions/setup-node action to v6

Author: renovate[bot]

.github/workflows/copilot-setup-steps.yml

@@ -16,7 +16,7 @@ jobs:
       contents: read
     steps:
       - uses: actions/checkout@v5
-      - uses: actions/setup-node@v5
+      - uses: actions/setup-node@v6
         with:
           node-version: '22'
           cache: npm

.github/workflows/main.yml

@@ -22,7 +22,7 @@ jobs:
         steps:
             - uses: actions/checkout@v5
 
-            - uses: actions/setup-node@v5
+            - uses: actions/setup-node@v6
               with:
                   cache: 'npm'
                   cache-dependency-path: 'package-lock.json'
@@ -55,7 +55,7 @@ jobs:
         steps:
             - uses: actions/checkout@v5
 
-            - uses: actions/setup-node@v5
+            - uses: actions/setup-node@v6
               with:
                   cache: 'npm'
                   cache-dependency-path: 'package-lock.json'
@@ -88,7 +88,7 @@ jobs:
         steps:
             - uses: actions/checkout@v5
 
-            - uses: actions/setup-node@v5
+            - uses: actions/setup-node@v6
               with:
                   cache: 'npm'
                   cache-dependency-path: 'package-lock.json'