chore(deps): update actions/checkout action to v6 (#117)

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

Author: renovate[bot]

.github/workflows/release-please.yml

@@ -36,7 +36,7 @@ jobs:
     if: ${{ needs.release-please.outputs.release_created }}
     steps:
       - name: checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           ref: ${{ needs.release-please.outputs.release_tag_name }}
 

.github/workflows/rust.yml

@@ -24,7 +24,7 @@ jobs:
           - stable
           - beta
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - uses: actions-rust-lang/setup-rust-toolchain@v1
         with:
@@ -40,7 +40,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - uses: actions-rust-lang/setup-rust-toolchain@v1
         with:
@@ -56,7 +56,7 @@ jobs:
   msrv:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions-rust-lang/setup-rust-toolchain@v1
         with:
           toolchain: stable