Toolchain 202601

[QuantumMisaka]

Reminder

• Have you linked an issue with this pull request?
• Have you added adequate unit tests and/or case tests for your pull request?
• Have you noticed possible changes of behavior below or in the linked issue?
• Have you explained the changes of codes in core modules of ESolver, HSolver, ElecState, Hamilt, Operator or Psi? (ignore if not applicable)

Unit Tests and/or Case Tests for my changes

• A unit test is modified for toolchain CI/CD

What's changed?

• Update Toolchain to version 202601
• remove legacy installer entrypoint
• use env var in install/setup in build_abacus*.sh
• other modification

Any changes of core modules? (ignore if not applicable)

• Example: I have added a new virtual function in the esolver base class in order to ...

In review. This version of toolchain have huge update from community collaborator @Growl1234