[BUG]: <title>Steps for building for qnx 7.1 and qnx 8.0

### vSomeip Version

MASTER

### Boost Version

1.74

### Environment

Ubuntu 22.04

### Describe the bug

I want to build the vsomeip3 stack and port it to QNX 7.1 and QNX 8.0.

I have already:

Built vsomeip for the host successfully.

Created the build directory and executed the steps as per the instructions provided.

I need:

Clear building steps for QNX (7.1 and 8.0).

Guidance on any changes needed for QNX builds.

Instructions on what to execute for build_qnx.

Support or references for publicly accessible dependencies, since some instructions reference private GitLab repos.

I want to complete the porting process and build the stack on QNX targets.

### Reproduction Steps

_No response_

### Expected behaviour

_No response_

### Logs and Screenshots

_No response_

Start by locating the existing build_qnx instructions and the dependency references mentioned in the issue. Document complete build steps for QNX 7.1 and 8.0, identify required QNX-specific changes, and replace private dependency references with publicly accessible alternatives where possible.

Written by the indexing model from the issue text.