docs(readme): fix v3.0 release note links

[RerankerGuo]

PR type

• Bug Fix
• New Feature
• Document Updates
• More Models or Datasets Support

PR information

Background

The English and Chinese README timelines still link to:

docs/source_en/Instruction/ReleaseNote3.0.md
docs/source/Instruction/ReleaseNote3.0.md

Both files were deleted in #7379, so the public README links now lead to
404 pages. The official v3.0.0 GitHub Release remains published and is
the stable source for this release information.

Changes

• Point the English ms-swift 3.0 timeline entry to the official
  v3.0.0 Release.
• Apply the same correction to the Chinese README.
• Keep all timeline text and other historical entries unchanged.

Verification

• Confirmed both old local targets do not exist.
• Confirmed https://github.com/modelscope/ms-swift/releases/tag/v3.0.0
  is a published, non-draft Release.
• Confirmed neither README retains a ReleaseNote3.0.md reference.
• .venv/bin/pre-commit run --all-files
• git diff --check

Impact

Documentation only. The change repairs two public README links without
affecting code, packaging, or runtime behavior.

Experiment results

Before the change, both relative targets were absent from the repository.
After the change, both README entries resolve to the published v3.0.0
Release page.

[gemini-code-assist]

Caution

The consumer version of Gemini Code Assist on GitHub has been sunset. All code review activity has officially ceased.