ci: bump GitHub Actions to node24 runtimes

actions/checkout@v4, actions/setup-node@v4 and cypress-io/github-action@v6
all run on the node20 action runtime, which GitHub is deprecating — hence the
"Node.js 20 is deprecated" warning on the Actions runner. Bump each to the
major that runs on node24:

- actions/checkout       v4 -> v5   (testing, e2e, publish)
- actions/setup-node     v4 -> v5   (testing, publish)
- cypress-io/github-action v6 -> v7 (e2e)

This is the action runtime only; the build/test Node (node-version 22.17.1)
is unchanged. cypress-io/github-action v7.0.0's sole breaking change is the
node20 -> node24 runtime bump, so the build/start/browser inputs are
unaffected.

Author: PiTrem

.github/workflows/e2e_testing.yml

@@ -6,9 +6,9 @@ jobs:
     runs-on: ubuntu-22.04
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
       - name: Cypress run
-        uses: cypress-io/github-action@v6
+        uses: cypress-io/github-action@v7
         with:
           build: npm run --max_old_space_size=12288 build
           start: npm --max_old_space_size=12288 start

.github/workflows/publish_package.yml

@@ -8,8 +8,8 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
+      - uses: actions/checkout@v5
+      - uses: actions/setup-node@v5
         with:
           node-version: 22.17.1
           registry-url: https://registry.npmjs.org/

.github/workflows/testing.yml

@@ -6,8 +6,8 @@ jobs:
   testing:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-node@v4
+      - uses: actions/checkout@v5
+      - uses: actions/setup-node@v5
         with:
           node-version: 22.17.1
       - run: yarn install --frozen-lockfile