Update actions/checkout@v6 -> v7

Author: dtolnay

.github/workflows/ci.yml

@@ -27,7 +27,7 @@ jobs:
         rust: [nightly, beta, stable, 1.85.0]
     timeout-minutes: 45
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
       - uses: dtolnay/rust-toolchain@master
         with:
           toolchain: ${{matrix.rust}}
@@ -55,7 +55,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 45
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
       - uses: dtolnay/rust-toolchain@1.71.0
         with:
           components: rust-src
@@ -68,7 +68,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 45
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
       - uses: dtolnay/rust-toolchain@nightly
       - run: cargo generate-lockfile -Z minimal-versions
       - run: cargo check --locked
@@ -82,7 +82,7 @@ jobs:
     env:
       RUSTDOCFLAGS: -Dwarnings
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
       - uses: dtolnay/rust-toolchain@nightly
         with:
           components: rust-src
@@ -95,7 +95,7 @@ jobs:
     if: github.event_name != 'pull_request'
     timeout-minutes: 45
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
       - uses: dtolnay/rust-toolchain@nightly
         with:
           components: clippy, rust-src
@@ -108,7 +108,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 45
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
       - uses: dtolnay/rust-toolchain@miri
       - run: cargo miri setup
       - run: cargo miri test
@@ -121,7 +121,7 @@ jobs:
     if: github.event_name != 'pull_request'
     timeout-minutes: 45
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
       - uses: dtolnay/rust-toolchain@stable
       - uses: dtolnay/install@cargo-outdated
       - run: cargo outdated --workspace --exit-code 1