chore(ci): bump remaining Node 20 actions (#6)

actions/cache v4 -> v5 (Node 24 runtime; no API change)
actions/upload-artifact v4 -> v7 (ESM + Node 24; existing name/path usage unaffected)

Clears the last Node 20 deprecation warnings surfaced during the
release run in d6ecbde.

.github/workflows/ci.yml

@@ -30,7 +30,7 @@ jobs:
         with:
           go-version: '1.25.x'
           check-latest: true
-      - uses: actions/cache@v4
+      - uses: actions/cache@v5
         with:
           path: |
             ~/go/pkg/mod
@@ -46,7 +46,7 @@ jobs:
         with:
           go-version: '1.25.x'
           check-latest: true
-      - uses: actions/cache@v4
+      - uses: actions/cache@v5
         with:
           path: |
             ~/go/pkg/mod
@@ -63,7 +63,7 @@ jobs:
         with:
           go-version: '1.25.x'
           check-latest: true
-      - uses: actions/cache@v4
+      - uses: actions/cache@v5
         with:
           path: |
             ~/go/pkg/mod
@@ -80,7 +80,7 @@ jobs:
         with:
           go-version: '1.25.x'
           check-latest: true
-      - uses: actions/cache@v4
+      - uses: actions/cache@v5
         with:
           path: |
             ~/go/pkg/mod
@@ -103,7 +103,7 @@ jobs:
         with:
           go-version: '1.25.x'
           check-latest: true
-      - uses: actions/cache@v4
+      - uses: actions/cache@v5
         with:
           path: |
             ~/go/pkg/mod
@@ -112,7 +112,7 @@ jobs:
       - run: go test -race -coverprofile=coverage.out ./...
       - name: Build all examples
         run: go build ./examples/...
-      - uses: actions/upload-artifact@v4
+      - uses: actions/upload-artifact@v7
         with:
           name: coverage
           path: coverage.out
@@ -125,7 +125,7 @@ jobs:
         with:
           go-version: '1.25.x'
           check-latest: true
-      - uses: actions/cache@v4
+      - uses: actions/cache@v5
         with:
           path: |
             ~/go/pkg/mod
@@ -146,7 +146,7 @@ jobs:
         with:
           go-version: '1.25.x'
           check-latest: true
-      - uses: actions/cache@v4
+      - uses: actions/cache@v5
         with:
           path: |
             ~/go/pkg/mod