Fix stray NBSP indentation in src/htmx.js

[marciomazza]

Description

Line 1180 was indented with non-breaking-space characters (U+00A0) instead of regular
spaces — almost certainly a copy-paste typo from #3924. Harmless to JS engines (NBSP is
valid whitespace), but if both the embedding page and this script lack a declared charset,
Chromium decodes the script as Windows-1252, mangling those bytes into a stray "Â" and
throwing a SyntaxError before window.htmx is ever defined. Reproduced live to confirm.

Swapped the NBSPs for normal spaces.

Testing

Confirmed no NBSP left in the file. Reproduced the failure in real Chromium (page + script
both charset-less) before the fix, confirmed it's gone after. Full suite: 1615 passed / 2
flaky, unrelated failures (reran those two alone, both pass).

Checklist

• I have read the contribution guidelines
• I have targeted this PR against the correct branch (master for website changes, dev for
  source changes)
• This is either a bugfix, a documentation update, or a new feature that has been explicitly
  approved via an issue
• I ran the test suite locally (npm run test) and verified that it succeeded

[MichaelWest22]

Yeah thanks i'm not sure how this happened. seems something went wrong with that recent edit of mine somehow!