docs: Remove rspack.core <1.6.0 constraint

[Copilot]

The rspack version was pinned to <1.6.0 due to upstream Docusaurus compatibility issues. Those issues are now resolved.

Changes

• Removed "@rspack/core": "<1.6.0" override from website/package.json
• Regenerated package-lock.json

rspack version now controlled by Docusaurus dependencies (currently 1.5.8), enabling automatic updates when Docusaurus adopts newer versions.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Remove rspack.core <1.6.0 constraint</issue_title>
<issue_description>Currently updating rspack to the newly released version 1.6.0 breaks the docs build and so the version has been pinned to <1.6.0.

Delete this constraint once the upstream repos are compatible with rspack 1.6.0</issue_description>

<agent_instructions>remove the rspack override in the website folder and regenerate lockfile</agent_instructions>

Comments on the Issue (you are @copilot in this section)

@vdusek once the upstream issues are resolved, remove this constraint in client and crawlee as well @janbuchar @Pijukatel @vdusek is there an upstream issue that you could link here so that we can easily check if the problem still exists? @Pijukatel I failed to identify where the problem is. I guessed that it was https://github.com/facebook/docusaurus/pull/11529, but their CI passed with such a bump, so it was probably something else.

I am planning just to watch the bumps and relax the constraint once some new passes. Recent one failed for example:
#722</comment_new>
<comment_new>@B4nan
the issue is fixed now, we just need to remove the constraint</comment_new>

• Fixes Remove rspack.core <1.6.0 constraint #659

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 67.92%. Comparing base (4e849a8) to head (71876d6).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #745   +/-   ##
=======================================
  Coverage   67.92%   67.92%           
=======================================
  Files          46       46           
  Lines        2681     2681           
=======================================
  Hits         1821     1821           
  Misses        860      860           

Flag	Coverage Δ
unit	67.92% <ø> (ø)

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