The issue was two-fold.
First of all, tsup starts using swc when `emitDecoratorMetadata` and `@swc/core` is installed.
`@swc/core` is installed transiently, which still causes the problem.
Okay, sure, so we move the `emitDecoratorMetadata` option to just
`packages/builders/tsconfig.json` seeing as the other packages don't use decorators anyway.
But that still leaves solving the issue for builders. @vladfrangu ended
up finding out that there was a bug in how esbuild handles plugins causing
the esbuild-plugin-version-injector plugin to not get loaded. This is solved
in v1.1.0 where the content is also replaced using the `onEnd` hook, if it
wasn't replaced by `onLoad` yet.