Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/build.yml

@@ -34,7 +34,7 @@ jobs:
 
         steps:
             -   name: Checkout
-                uses: actions/checkout@v3
+                uses: actions/checkout@v6
 
             -   name: Set up cache for ~./m2/repository
                 uses: actions/cache@v5
@@ -71,7 +71,7 @@ jobs:
             - build
         steps:
             -   name: Check out
-                uses: actions/checkout@v3
+                uses: actions/checkout@v6
                 with:
                     fetch-depth: 0
             -   run: exit 1

.github/workflows/release.yml

@@ -22,7 +22,7 @@ jobs:
 
         steps:
             -   name: Check out
-                uses: actions/checkout@v3
+                uses: actions/checkout@v6
                 with:
                     fetch-depth: 0