ci: added a common way to disable perf workflow

This allows a quick disable of all but one workflow to debug
a new CI behavior.

The way is to substitue '**-notest' with 'your-branch-name'
temporarily on other workflows while debugging the target workflow.

Author: tmr-g

.github/workflows/performance.yml

@@ -3,6 +3,7 @@ name: Performance
 on:
   push:
     branches-ignore:
+      - '**-notest'
       - '**-noperf'
       - 'tarantool/release/**'
       - 'upstream-**'