rust: downgrad prost-build to 0.14.1

[florianl]

Fix the rust error, that is shown in https://github.com/open-telemetry/opentelemetry-ebpf-profiler/actions/runs/20454325313/job/58773196338?pr=1035:

error: package `prost-build v0.14.2` cannot be built because it requires rustc 1.82 or newer, while the currently active rustc version is 1.77.2
Either upgrade to rustc 1.82 or newer, or use
cargo update prost-build@0.14.2 --precise ver

This is more of a quick fix for #1035 rather than a proper solution. The proper way will be to update the used rust version.

[florianl]

Superseeded by #1038