Fix indent=tab normalization for quoted and capitalized .isort.cfg values

[pradip-pawar1]

Fixes #2693

.isort.cfg values like indent="tab" (quoted) or indent=Tab (capitalized) were silently falling back to spaces instead of producing a real tab, because the auto-discovery config path (via find_all_configs/Trie) never ran the existing quote-stripping/tab- normalization logic — that logic only applied when an explicit --settings-path was given.

This moves the normalization into _get_config_data() itself, the function both paths share, so auto-discovered and explicitly-pathed configs behave consistently.

Known remaining limitation: a literal tab byte or escaped \t/\\t in the config value are not normalized — configparser strips whitespace-only values before this code runs, and escape sequences aren't something this fix attempts to interpret. Users should write the word tab or Tab.

[shan3520]

Thanks for picking this up! A few things I noticed while testing this against main:

• I couldn't reproduce the premise that auto-discovered configs skip normalization. On unmodified main, indent=tab, indent=Tab and indent="tab" in .isort.cfg all produce a real tab, both with default config discovery and with --resolve-all-configs. The existing normalization in Config.__init__ runs for both paths, so the new branch in _get_config_data() doesn't change the outcome for these values.
• Related to that, test_indent_tab_config_normalization passes on main without this change, since it builds Config(indent=...) directly and that already handles "tab" / Tab.
• The one case that is actually broken is indent=\t, which is used literally and makes isort write invalid Python (see my comment on indent=Tab setting not respected #2693). I have a small fix with tests for that on a branch (shan3520/isort@issue/2693) and I'm happy to fold it in however the maintainers prefer.
• The .gitignore change (myUse/) looks like it was included by accident.

(Testing done with help from Claude; results verified locally.)

[pradip-pawar1]

Thank you for digging into this and testing against clean main — you're right, I can't reproduce the normalization gap either now that I've rechecked. My original reproduction must have been run against a contaminated environment; I missed that config_overrides merges into combined_config unconditionally, so the existing logic already covers both paths. Appreciate you catching this before it went further.

You're also right about the .gitignore change — that was accidental, not meant for this PR.

Given #2708 already has a real fix with tests for the actual indent=\t bug, I'll close this PR rather than duplicate effort. Thanks again for the careful review.