Bump actions/cache from 3 to 4 (#259)

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

Author: dependabot[bot]

.github/workflows/deploy-11ty-pages.yml

@@ -29,13 +29,13 @@ jobs:
           node-version: "18.x"
 
       - name: Persist npm cache
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ~/.npm
           key: ${{ runner.os }}-node-${{ hashFiles('**/package.json') }}
 
       - name: Persist Eleventy .cache
-        uses: actions/cache@v3
+        uses: actions/cache@v4
         with:
           path: ./.cache
           key: ${{ runner.os }}-eleventy-fetch-cache