chore(deps): update actions/checkout action to v6 (#89)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/ci.yml

@@ -13,7 +13,7 @@ jobs:
     name: 'Lint: node-18, ubuntu-latest'
     steps:
       - name: Checkout
-        uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
         with:
           fetch-depth: 0
 
@@ -34,7 +34,7 @@ jobs:
     name: 'Format: node-18, ubuntu-latest'
     steps:
       - name: Checkout
-        uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
         with:
           fetch-depth: 0
 
@@ -55,7 +55,7 @@ jobs:
     name: 'TS-Check Tests: node-18, ubuntu-latest'
     steps:
       - name: Checkout
-        uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
         with:
           fetch-depth: 0