Draft: [CI] Speedup prepare_instrumentation.sh

• Related issues: N/A
• Requested reviewers: @kiene, @pihlajakuja, @malenovsky

Reason why this change is needed

• The instrumentation script takes a significant amount of time to run, optimizations can be beneficial for CI

Description of the change

• Coan/WMC Tool calls have been parallelized
• On my system (Debian 12, i7-10700) this cuts runtime from ~135 seconds to ~75 seconds

Affected operating points

• CI