[CashTab] Update react-copy-to-clipboard

Summary: this was the last module to not explicitely depend on react 7. Now the whoel set of dependencies is consistent and we can let npm do its magic without invoking flags to force it to.

Test Plan:

npm run start

Then use the wallet and check that it works as expected.

Reviewers: #bitcoin_abc, majcosta

Reviewed By: #bitcoin_abc, majcosta

Differential Revision: https://reviews.bitcoinabc.org/D8901