chore(deps): bump actions/setup-node from 4 to 6

Bumps [actions/setup-node](https://github.com/actions/setup-node) from 4 to 6.
- [Release notes](https://github.com/actions/setup-node/releases)
- [Commits](actions/setup-node@v4...v6)

---
updated-dependencies:
- dependency-name: actions/setup-node
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/cd-firefox.yml

@@ -65,7 +65,7 @@ jobs:
 
       - name: Set up Node.js
         if: steps.secrets.outputs.configured == 'true'
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@v6
         with:
           node-version: 22
 

.github/workflows/ci.yml

@@ -12,7 +12,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v6
         with:
           node-version: 22
 
@@ -63,7 +63,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v6
         with:
           node-version: 22
 
@@ -81,7 +81,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v6
         with:
           node-version: 22
 

.github/workflows/docs.yml

@@ -15,7 +15,7 @@ jobs:
       contents: write
     steps:
       - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v6
         with:
           node-version: '22'
       - run: node scripts/generate-docs.js

.github/workflows/maintenance.yml

@@ -30,7 +30,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v6
         with:
           node-version: 22
 
@@ -85,7 +85,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v6
         with:
           node-version: 22
 
@@ -150,7 +150,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v6
         with:
           node-version: 22