PR: Fix several errors with missing plugins when setting a layout

[ccordoba12]

Description of Changes

• We were not setting layouts correctly if the first plugin in the layout's area is missing.
• Also, tabify any plugin not available during the previous session (before we were doing that only for external plugins). That will include internal plugins that were automatically disabled in the first session (e.g. Help).
• I found these problems while testing Spyder without WebEngine.

Issue(s) Resolved

Fixes #

Affirmation

By submitting this Pull Request or typing my (user)name below,
I affirm the Developer Certificate of Origin
with respect to all commits and content included in this PR,
and understand I am releasing the same under Spyder's MIT (Expat) license.

I certify the above statement is true and correct: @ccordoba12

[pep8speaks]

Hello @ccordoba12! Thanks for updating this PR. We checked the lines you've touched for PEP 8 issues, and found:

• In the file spyder/plugins/layout/api.py:

Line 465:54: E203 whitespace before ':'

Comment last updated at 2024-07-25 17:21:56 UTC