"Create APM agent key" doesn't prevent multiple-clicks

[ty-elastic]

Kibana version: 8.14.3

Elasticsearch version: 8.14.3

Server OS version: ESS

Browser version: Chrome 126

Browser OS version: MacOS Sonoma 14.5

Original install method (e.g. download page, yum, from source, etc.):

Describe the bug:

it is pretty easy to accidentally create duplicative apikeys.. if you accidentally click more than once on the "Create APM agent key" before Kibana dismisses the flyover, it seems to (re-)call the create API function with the same parameters and create duplicative API keys.

Steps to reproduce:

1. Navigate to Observability / APM
2. Click Settings in upper-right
3. Click "Agent Keys"
4. Click "Create APM agent key"
5. Name your key like "test"
6. Rapidly click "Create APM agent key" before flyover disappears

Expected behavior:

After 1 click, you should be locked out of clicking "Create APM agent key" on the flyover

Screenshots (if relevant):

this is kind of a ridiculous example, but i've found myself with 2 keys once and awhile if i'm sloppy on the click.

Errors in browser console (if relevant):

Provide logs and/or server output (if relevant):

Any additional context:

[elasticmachine]

Pinging @elastic/obs-ux-infra_services-team (Team:obs-ux-infra_services)