chore(deps): update actions/cache action to v6

Author: renovate[bot]

.github/workflows/main.yml

@@ -30,7 +30,7 @@ jobs:
 
       - name: Cache Go tools
         id: go-tools-cache
-        uses: actions/cache@v5
+        uses: actions/cache@v6
         with:
           path: ~/go/bin
           key: ${{ runner.os }}-go-tools-${{ hashFiles('.mise.toml') }}

.github/workflows/pr-checks.yml

@@ -30,7 +30,7 @@ jobs:
 
       - name: Cache Go tools
         id: go-tools-cache
-        uses: actions/cache@v5
+        uses: actions/cache@v6
         with:
           path: ~/go/bin
           key: ${{ runner.os }}-go-tools-${{ hashFiles('.mise.toml') }}