GitHub Action: Bump actions/checkout from 6 to 7 (#439)

Bumps the all-actions-dependencies group with 1 update:
[actions/checkout](https://github.com/actions/checkout).

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/prepare-binaries.yml

@@ -32,7 +32,7 @@ jobs:
 
     steps:
     - name: Checkout Self
-      uses: actions/checkout@v6
+      uses: actions/checkout@v7
 
     - name: Generate Token
       if: github.event_name == 'release'

.github/workflows/validate-kek-updates.yml

@@ -24,7 +24,7 @@ jobs:
 
     steps:
     - name: Checkout PR
-      uses: actions/checkout@v6
+      uses: actions/checkout@v7
       with:
         fetch-depth: 0  # Need full history to compare with base branch