Update npm dependencies, remove direct semver dependency

[glennmatthews]

Closes: #n/a

What's Changed

• Remove unneeded direct dependency on semver package (only used in one place in start.js, to check for an obsolete version of react that we'll never see). This should address a Dependabot security alert.
• Run npm update to update dependencies in general.

TODO

• Explanation of Change(s)
• Added change log fragment(s) (for more information see the documentation)
• n/a Attached Screenshots, Payload Example
• n/a Unit, Integration Tests
• n/a Documentation Updates (when adding/changing features)
• n/a Example Plugin Updates (when adding/changing features)
• Outline Remaining Work, Constraints from Design