async and bsec v3 support

[1NFR4R3D]

Are there any plans to support async runtimes? A project I'm working on heavily uses async code, and this is one of the last non-async projects.

I'm also curious about supporting newer versions of BSEC; Bosch have released v3.x in 2025. Are there any plans to support that?

I'll be happy to provide a PR, just might take some time.

[fgardt]

I got a project that uses a BME690 so if you‘re not quicker than me I might also give updating this to BSEC v3 a shot.

[jgosmann]

At the moment I don't have the capacity to look into it myself.