Disable caching of index.html in s3gw-ui via ingress

[votdev]

The ingress we deploy for the s3gw-ui should add custom headers to disable caching of index.html. This way the file will always be loaded from the server which ensures that changes to the assets (e.g. JS files hashed by Angular) are applied. Otherwise, changes to the s3gw-ui might not be visible to the user because the SPA is not updated as it is cached by the browser.

Necessary headers for index.html:

• Cache-Control: no-cache, max-age=0, must-revalidate
• Expires: 0
• Pragma: no-cache

[votdev]

Obsolete by s3gw-tech/s3gw-ui#268 which adds the headers via FastAPI.