add support for fetch timeout control for node_helpers, fix timeouts on armv6l (#3660)

user reporting slow/no connection/timeout errors on armv6l for calendar,
and newsfeed

we can increase the timeout by adding calls to the undici lib, but it
requires node 20.18.1 or above.

this adds the support for timeout
(also environment variable to override if needed,, mmFetchTimeout
(default 30 seconds)

and updates the base node version

.github/workflows/automated-tests.yaml

@@ -38,7 +38,7 @@ jobs:
     timeout-minutes: 30
     strategy:
       matrix:
-        node-version: [20.9.0, 20.x, 22.x, 23.x]
+        node-version: [20.18.1, 20.x, 22.x, 23.x]
     steps:
       - name: "Checkout code"
         uses: actions/checkout@v4

.github/workflows/electron-rebuild.yaml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node-version: [20.9.0, 20.x, 22.x, 23.x]
+        node-version: [20.18.1, 20.x, 22.x, 23.x]
     steps:
       - name: Checkout code
         uses: actions/checkout@v4