Fix airflowctl auth login failing with trailing slash in api-url

[emin-ozata]

Description

closes: #61244
Fixes an authentication failure triggered when airflowctl auth login --api-url is given a base URL with a trailing slash.

Problem

When users copy the Airflow base URL from their browser's address bar (which typically includes a trailing slash), the _get_base_url()
method concatenates it directly with path segments, creating malformed URLs with double slashes (e.g., http://localhost:8080//auth),
resulting in "Method Not Allowed" errors.

Solution

Normalize the base URL by stripping trailing slashes before constructing endpoint paths using rstrip("/") in the _get_base_url()
method.

Testing

Added test cases to verify URLs with trailing slashes are handled correctly for both CLI and AUTH client kinds.

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Related Issues

• airflowctl auth login fails when --api-url ends with trailing slash #61244

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---

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[boring-cyborg]

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[Prab-27]

LGTM !!

[Prab-27]

Thanks @emin-ozata !!

The URL Pattern mentioned in the doc The URL should be in the form of http(s)://<host>:<port>- here

This is helpful, since one could easily include it by mistake.

cc : @bugraoz93 - Could you please share your insight on this when you have some time ?

[bugraoz93]

Thanks @emin-ozata !!

The URL Pattern mentioned in the doc The URL should be in the form of http(s)://<host>:<port>- here

This is helpful, since one could easily include it by mistake.

cc : @bugraoz93 - Could you please share your insight on this when you have some time ?

Agree, indeed, copy & paste from browsers can cause it, or similar. It makes sense!

[bugraoz93]

Let's see the CI, and then we can merge it. Thanks @emin-ozata!

[bugraoz93]

I added for you, but if you add closes:#<issue_number> or relates:#<issue_numer> It will automatically update the issue you have created

[boring-cyborg]

Awesome work, congrats on your first merged pull request! You are invited to check our Issue Tracker for additional contributions.

[bugraoz93]

Congrats @emin-ozata! 🎉