Intermittant UI CI failures

[a3957273]

One of our UI tests is flaky, which is making merging new features harder. Example:

https://github.com/gchq/CyberChef/actions/runs/7770605606/job/21190991013?pr=1555

>> ✖ NightwatchAssertError
>>    Timed out while waiting for element <#stale-indicator> to not be visible for 5000 milliseconds. - expected "not visible" but got: "visible" (5122ms)
>> 
>>     Error location:
>>     /home/runner/work/CyberChef/CyberChef/tests/browser/browserUtils.js:
>>     –––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––
>>      51 |     browser
>>      52 |         .click("#bake")
>>      53 |         .waitForElementNotVisible("#stale-indicator", 5000) 
>>      54 |         .waitForElementNotVisible("#output-loader", 5000);
>>      55 | }
>>     –––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

  FAILED: 1 assertions failed and  8 passed (5.552s)

───────────────────────────────────────────────────────────────────────────────────────────────────

  ️TEST FAILURE (50.092s):  
   - 1 other test suites were aborted; 
   - 1 assertions failed; 742 passed
   - 1 skipped

   ✖ 1) 01_io

   – Loading from URL (5.552s)

   → ✖ NightwatchAssertError
   Timed out while waiting for element <#stale-indicator> to not be visible for 5000 milliseconds. - expected "not visible" but got: "visible" (5122ms)

    Error location:
    /home/runner/work/CyberChef/CyberChef/tests/browser/01_io.js:
    ––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––
     657 |         browser.expect.element("#output-text .eol-value").text.that.equals("PS");
     658 | 
     659 |         utils.bake(browser); 
     660 | 
     661 |         browser.expect.element(`#output-text .cm-content`).to.have.property("textContent").match(/^.{44}$/);
    ––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

    SKIPPED:
    - Replace input with output

 Wrote HTML report file to: /home/runner/work/CyberChef/CyberChef/tests/browser/output/nightwatch-html-report/index.html

>> ✖ NightwatchAssertError
>>    Timed out while waiting for element <#stale-indicator> to not be visible for 5000 milliseconds. - expected "not visible" but got: "visible" (5122ms)
>> 
>>     Error location:
>>     /home/runner/work/CyberChef/CyberChef/tests/browser/browserUtils.js:
>>     –––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––
>>      51 |     browser
>>      52 |         .click("#bake")
>>      53 |         .waitForElementNotVisible("#stale-indicator", 5000) 
>>      54 |         .waitForElementNotVisible("#output-loader", 5000);
>>      55 | }
>>     –––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

>> Exited with code: 10.
>> Error executing child process: Error: Process exited with code 10.