Not required @types/bignumber.js removed from package.json in web3-core

[nivida]

Description

Fixes #3209

Type of change

• Dependencies

Checklist:

• I have selected the correct base branch.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.
• Any dependent changes have been merged and published in downstream modules.
• I ran npm run test with success and extended the tests if necessary.
• I ran npm run build and tested the resulting file from dist folder in a browser.
• I have tested my code on the live network.

[coveralls]

Coverage remained the same at 84.347% when pulling acbb039 on issue/3209 into e252b8c on 1.x.