Ruby gem: Pyroscope.tag_wrapper cause panic in case pyroscope is not configured

**Describe the bug you encountered:**

```
$ pry
[1] pry(main)> require "pyroscope"
=> true
[2] pry(main)> Pyroscope.tag_wrapper("a" => "b")
thread '' panicked at 'called `Result::unwrap()` on an `Err` value: Io(Os { code: 2, kind: NotFound, message: "No such file or directory" })', src/lib.rs:298:64
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
fatal runtime error: failed to initiate panic, error 5
Abort trap: 6
```
---

**pyroscope-rs version and environment**

pyroscope (0.5.10) gem