accessor keyword not supported

[Typescript 4.9 introduced a new keyword](https://devblogs.microsoft.com/typescript/announcing-typescript-4-9/#auto-accessors-in-classes) `accessor` to automatically make a property private and generate its accessors.

If I try to compile code that uses this keyword, I get the following error:
```
$ tsup src/index.ts --format esm --dts --clean
CLI Building entry: src/index.ts
CLI Using tsconfig: tsconfig.json
CLI tsup v6.6.3
CLI Target: es2022
CLI Cleaning output folder
ESM Build start
✘ [ERROR] Expected ";" but found "fieldName"
```

I rewrote my code to not use the keyword and it compiles perfectly.

Also, I compiled the code containing the keyword `accessor` using `tsc` and it is compiled properly.

So I suppose it's a compatibility issue with the last version of Typescript?

Start by reproducing the failure with the reported `tsup src/index.ts --format esm --dts --clean` command and compare it with the successful `tsc` compilation. Trace how tsup parses TypeScript containing the `accessor` keyword, then verify that the same example builds successfully after the compatibility issue is addressed.

Written by the indexing model from the issue text.