chore(deps): update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/release.yml

@@ -18,7 +18,7 @@ jobs:
       NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           persist-credentials: false
 

.github/workflows/testing.yml

@@ -12,7 +12,7 @@ jobs:
         node-version: [22, 24]
     steps:
       - name: Check out code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Enable Corepack
         run: corepack enable
@@ -37,7 +37,7 @@ jobs:
       matrix:
         node-version: [24]
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Enable Corepack
         run: corepack enable
@@ -82,7 +82,7 @@ jobs:
         node-version: [24]
     steps:
       - name: Check out code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0