[Cashtab] Running npm audit fix

Summary:
T2701

Now that minimal-slp-wallet is out, simple fix to resolve dependency tree issues

This diff was created by running npm audit fix in the web/cashtab directory

Test Plan:
npm audit
Note 0 issues

Reviewers: #bitcoin_abc, emack

Reviewed By: #bitcoin_abc, emack

Differential Revision: https://reviews.bitcoinabc.org/D12835