chore(ACI): Remove references to SentryAppIdentifier

[ceorourke]

Now that we've migrated the Action data to only ever have a sentry app id (and not an installation uuid) we can remove references to the sentry app identifier as it was only used to differentiate between actions with a sentry app id and actions with a sentry app installation uuid.

Closes ISWF-2034

[linear]

ISWF-2034 Remove front end references to sentry app identifier

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

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[sentry]

Bug: Creating new Sentry App actions will fail because the frontend no longer sends the required sentry_app_identifier field, which the backend still expects for validation.
_{Severity: HIGH}

Suggested Fix

Update the getDefaultConfig() function in automationBuilderContext.tsx to include the sentryAppIdentifier field in the returned configuration object for new Sentry App actions. This will align the frontend payload with the backend's required schema and allow new actions to be saved successfully.

Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI
agent.
Verify if this is a real issue. If it is, propose a fix; if not, explain why it's not
valid.

Location: static/app/views/automations/components/actionNodeList.tsx#L51

Potential issue: When creating a new Sentry App action, the frontend configuration
generated by `getDefaultConfig()` in `automationBuilderContext.tsx` no longer includes
the `sentryAppIdentifier` field. However, the backend schema defined in
`sentry_app_handler.py` still lists `sentry_app_identifier` as a required field.
Consequently, any attempt to save a new Sentry App action from the user interface will
result in a backend validation error, preventing users from successfully creating these
automations.

[ceorourke]

This will not be merged until #107174 is merged first.