Running `npm test` for VSCode extension in Jenkins CI crashes - visual-studio-code

Question

I have a Jenkins CI setup to run tests for my VS Code extension. I setup the container as is detailed in the Continuous Integration page in the VS Code documentation https://code.visualstudio.com/api/working-with-extensions/continuous-integration.
apt update
apt install -y libasound2 libgbm1 libgtk-3-0 libnss3 xvfb
I then run tests as follows
xvfb-run -a npm run test
This was working fine up until very recently when my tests starting taking a little longer than they did before. I now get the following error messages half way through my test run.
16:27:34 [main 2023-02-06T15:27:34.720Z] CodeWindow: renderer process gone (reason: crashed, code: 133)
16:27:34
16:27:34 [main 2023-02-06T15:27:34.723Z] [UtilityProcess id: 1, type: extensionHost, pid: 413]: waiting to exit...
16:27:34
16:27:34 [main 2023-02-06T15:27:34.736Z] [UtilityProcess id: 1, type: extensionHost, pid: 413]: received exit event with code 0
16:27:34 [main 2023-02-06T15:27:34.737Z] Extension host with pid 413 exited with code: 0, signal: unknown.
16:27:34
16:27:34 Error sending from webFrameMain: Error: Render frame was disposed before WebFrameMain could be accessed
16:27:34 at s.send (node:electron/js2c/browser_init:173:631)
16:27:34 at g.send (node:electron/js2c/browser_init:169:2657)
16:27:34 at E.send (/tmp/code/.vscode-test/vscode-linux-x64-1.75.0/VSCode-linux-x64/resources/app/out/vs/code/electron-main/main.js:16:77328)
...
and the test run fails. This doesn't seem related to the tests as it can occur at slightly different times in the test run. It just seems like running VS Code tests will fail if they take too long.
What can I do to avoid this?