Enable historyUpdateUrl for local files

[ananyapahwa]

Summary:

This PR enables the historyUpdateUrl preference to work with local PDF files (file:// protocol), allowing the browser to remember and restore the last viewed position when the preference is enabled.

Problem:

Currently, the historyUpdateUrl preference only updates the URL hash for web-based PDFs. Local PDF files are explicitly excluded from this feature, even when the user has enabled the preference in about:config. This inconsistency means users cannot benefit from position restoration when viewing local files.

Solution:

Removed the protocol check that prevented file:// URLs from updating the browser history. The change is minimal and focused:

• Modified web/pdf_history.js to remove the if (protocol !== "file:") condition in the #pushOrReplaceState method
• This allows local files to update the URL hash (e.g., #page=5) when scrolling, just like web-based PDFs

Testing:

1. All unit tests pass (npx gulp unittestcli - 1055 specs, 0 failures)
2. Linting passes (npx gulp lint)
3. The change leverages the existing historyUpdateUrl preference mechanism without introducing new code paths

Related Issue:

Fixes : #20370

Note: This change only affects behavior when users explicitly enable pdfjs.historyUpdateUrl in Firefox preferences. The default behavior remains unchanged.