ci: remove test-stable-perf

[yihau]

Problem

we don't run test-stable-perf for years also we have a plan to remove CUDA support: #3817

Summary of Changes

remove unused ci scripts

[t-nelson]

do we still have coverage for the cpu logic in perflib after this?

[yihau]

I checked the test-stable-perf. It looks like it enables CUDA and then re-runs some package tests (solana-perf, solana-ledger, solana-core) and poh-bench test. could you remind me how do we check cpu logic in perflib 🤔

btw, I guess it can be another PR 🙈

[t-nelson]

n/m looks like we should be covered still