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

Author: renovate[bot]

.github/workflows/cd.yml

@@ -19,7 +19,7 @@ jobs:
       - name: Set up Mise Environment
         uses: jdx/mise-action@v3
       - name: Cache Go modules
-        uses: actions/cache@v5
+        uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6
         with:
           path: |
             ~/.cache/go-build

.github/workflows/ci.yml

@@ -23,7 +23,7 @@ jobs:
         uses: jdx/mise-action@v3
 
       - name: Cache Go Modules
-        uses: actions/cache@v5
+        uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6
         with:
           path: |
             ~/.cache/go-build