fix(build): bundle pure esm package

[Thiry1]

Summary

When using the openapi-typescript-code-generator as CJS, the following error occurs.

❯ node --input-type=commonjs -e "require('./dist/index.cjs')"
/Users/kei_sakamoto/workspace/openapi-typescript-code-generator/dist/index.cjs:1377
var DotProp2 = __toESM(require("dot-prop"), 1);
                       ^

Error [ERR_REQUIRE_ESM]: require() of ES Module /Users/kei_sakamoto/workspace/openapi-typescript-code-generator/node_modules/.pnpm/[email protected]/node_modules/dot-prop/index.js from /Users/kei_sakamoto/workspace/openapi-typescript-code-generator/dist/index.cjs not supported.
Instead change the require of index.js in /Users/kei_sakamoto/workspace/openapi-typescript-code-generator/dist/index.cjs to a dynamic import() which is available in all CommonJS modules.
    at Object.<anonymous> (/Users/kei_sakamoto/workspace/openapi-typescript-code-generator/dist/index.cjs:1377:24)
    at [eval]:1:1
    at Script.runInThisContext (node:vm:122:12)
    at Object.runInThisContext (node:vm:296:38)
    at [eval]-wrapper:6:24 {
  code: 'ERR_REQUIRE_ESM'
}

To resolve this issue, we need to bundle pure esm package.
However, tsup does not bundle packages that are listed in the dependencies.(see https://tsup.egoist.dev/#excluding-packages , egoist/tsup#628 (comment))
As a workaround, I moved the pure ESM package to devDependencies.

Test Plan

verify that the package can be loaded in both ESM and CJS with the following command.

node --input-type=module -e "import {CodeGenerator} from './dist/index.js'"
node --input-type=commonjs -e "require('./dist/index.cjs')"

[Thiry1]

Some tests are failing.I am investigating it.

It only occurs locally.

[Himenon]

Thank you for the pull request. Is there anything we should include in our README about this change?

@Thiry1

[Thiry1]

@Himenon

Is there anything we should include in our README about this change?

I believe there is no impact on users, so I think it is unnecessary to add anything to the README.

[Himenon]

Yes, sir. Thank you!

[Himenon]

This changes was included in v1.0.9