fix: ESM module types

[petertonysmith94]

Closes: #1776

---

Summary

Using AreTheTypesWrong, we can see that our ESM distributions have the following issues.

• 🎭 Masquerading as CJS
• 🐛 Used fallback condition
  

Demo

# Install
mkdir fixed-esm &&
  cd fixed-esm &&
  pnpm init &&
  pnpm install "@fuel-ts/abi-typegen@0.0.0-pr-1889-20240404191825" &&
  echo 'import "@fuel-ts/abi-typegen";' > main.mjs

# Run
node main.mjs

Note: if you install the latest for @fuel-ts/abi-typegen the following error will be occur.

[github-actions]

This PR is published in NPM with version 0.0.0-pr-1889-20240405150458

[github-actions]

Coverage Report:

Lines	Branches	Functions	Statements
81.04%(-0.01%)	71.6%(+0%)	79.09%(+0%)	81.12%(-0.01%)

Changed Files:

Coverage values did not change👌.

[petertonysmith94]

Upgraded tsup to 8.0.0. We could go to 7.1.0 to allow for the following change, which enables the correct type files to be generated.

[petertonysmith94]

Superseded by #2060