Potential Race Condition or Garbage Collection Issue during JNI Environment Usage

## Description
The issue arises when a JVM exception is thrown before invoking JNI code, leading to a garbage collection and race condition problem. This results in the `env` variable not existing in the following [line:](https://github.com/deepjavalibrary/djl/blob/master/extensions/tokenizers/rust/src/lib.rs#L440C17-L442C31)

```rust
let obj = env.new_object_unchecked(cls, constructor, &offsets_vec[..]).unwrap();
```

## Expected Behavior

The expected behavior is for the environment object to be properly accessible. It would be nice if an exception were thrown instead of the JVM being crashed.

## Error Message
```
thread '' panicked at src/lib.rs:442:22:
called `Result::unwrap()` on an `Err` value: JavaException
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
fatal runtime error: failed to initiate panic, error 5
rlwrap: warning: clojure crashed, killed by SIGABRT (core dumped).
rlwrap itself has not crashed, but for transparency,
it will now kill itself with the same signal
```

## How to Reproduce?

The error can most effectively be replicated by employing infinite recursion to generate tokens. I not providing a specific example because we use Clojure, which has too many parentheses to fit into an example.

## Steps to reproduce

Like above.

## What have you tried to solve it?

- Reviewing the rust/JNI code

## Environment Info

Since the issue is related to JNI and JVM interaction, rather than a problem specific to the DJL framework, running ./gradlew debugEnv as suggested might not provide the relevant environmental information needed to debug this issue.