Update version to v3.11.0-beta6

[ZhouXY-PKU]

Reminder

• [v] I have read AGENTS.md and docs/developers_guide/agent_governance.md.
• [v] I have linked an issue or explained why this PR does not need one.
• I have added adequate unit tests and/or case tests, or explained why not.
• I have listed the exact verification commands run and their results.
• I have described user-visible behavior changes, including INPUT parameter changes.
• I have explained core-module impact for ESolver, HSolver, ElecState, Hamilt, Operator, Psi, or other source/ changes.
• I have requested any needed governance exception below.

Linked Issue

Just a typo.

Unit Tests and/or Case Tests for my changes

• Commands run: N\A
• Result summary: N\A
• Checks not run, with reason: N\A

What's changed?

• A new beta version.

Governance Notes

• INPUT/docs changes: No
• Core module impact: No
• Exceptions requested:

[github-actions]

Agent Governance Check

Severity	Rule	Location	Reason	Suggested action	Exception
warning	Test evidence review	pull_request.body	Source code changed without test path changes or PR test evidence.	Add focused tests, update a relevant case, or document why tests are not required.	allowed
warning	Documentation sync review	pull_request.body	Source changes have no docs change or explicit no-docs-needed statement.	Add documentation updates for behavior/interface changes, or state why documentation is not required.	allowed