Cannot use import statement outside a module in 16.5.0

[mefellows]

In #1731 we merged a change that included an upstream dependency with ESM

The initial build was red but after the examples were re-worked to use vite, the build started passing and this slipped in an auto-merge.

Software versions

Consumer Pact library: 16.5.0

Expected behaviour

No errors when loading Pact.

Actual behaviour

When Pact is used in Jest on a non-ESM environment, you see:

SyntaxError: Cannot use import statement outside a module
  (https-proxy-agent@9.1.0/dist/index.js)