Fix: document title no longer updated for responses suppressed by noSwap

[alizamani1616]

Description

When a response status matches htmx.config.noSwap — the default [204, 304], or "4xx"/"5xx" pushed by the htmx-2-compat extension — htmx correctly skips swapping the response content, but if the response body contained a <title>, the document title was still updated:

<meta name="htmx-config" content='{"noSwap":[204,304,"4xx","5xx"]}'>

A 404/500 response with <title>Error</title> in the body silently changed the page title even though nothing was swapped.

htmx 2 never touched the title for a response that was not swapped, and noSwap is the documented way to restore htmx 2 behavior, so it should not update the title either.

Fixes #4113

Root cause

__handleStatusCodes marks the response as non-swappable by setting ctx.swap = "none", and swap() still runs (events, indicators, OOB handling). The title update at the end of swap() only checked ignoreTitle, so the none swap style coming from noSwap still updated document.title.

Fix

• __handleStatusCodes sets ctx.noSwap = true alongside ctx.swap = "none" when the status matches the noSwap config.
• swap() skips the title update when ctx.noSwap is set.

Explicit hx-swap="none" and hx-status:*="swap:none" overrides still update the title, matching htmx 2 behavior, since they represent a deliberate swap specification rather than status-based suppression.

Testing

• Added unit tests for the noSwap flag in test/tests/unit/__handleStatusCodes.js (set for exact and wildcard patterns, not set for swappable statuses or hx-status overrides).
• Added title unit tests in test/tests/unit/swap.js: no title update with noSwap: true, title still updates for plain swap: "none" without the flag.
• Verified in a real browser: with noSwap: ["4xx","5xx"], a 404 response containing <title>Error</title> no longer changes document.title; before the fix it changed it to "Error" while the content stayed unswapped, exactly as reported.

Full suite passes: 1742 tests, 0 failures, 100% coverage of src/htmx.js.