Update actions/setup-node action to v6

GitOrigin-RevId: e40ae8ec0cf33226472c9f019151881f278456e2

Author: mapbox-renovate[bot]

.github/workflows/ci.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v7
-    - uses: actions/setup-node@v4
+    - uses: actions/setup-node@v6
       with:
         node-version-file: '.nvmrc'
         cache: npm
@@ -36,7 +36,7 @@ jobs:
       contents: read
     steps:
     - uses: actions/checkout@v7
-    - uses: actions/setup-node@v4
+    - uses: actions/setup-node@v6
       with:
         node-version-file: '.nvmrc'
         cache: npm
@@ -66,7 +66,7 @@ jobs:
       contents: read
     steps:
     - uses: actions/checkout@v7
-    - uses: actions/setup-node@v4
+    - uses: actions/setup-node@v6
       with:
         node-version-file: '.nvmrc'
         cache: npm