deps(forge init): update to checkout v6 in default templates (#12731)

update to checkout v6

Author: zerosnacks

crates/forge/assets/solidity/workflowTemplate.yml

@@ -17,7 +17,7 @@ jobs:
     permissions:
       contents: read
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           persist-credentials: false
           submodules: recursive

crates/forge/assets/vyper/workflowTemplate.yml

@@ -17,7 +17,7 @@ jobs:
     permissions:
       contents: read
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           persist-credentials: false
           submodules: recursive