These 8 workflows install uv but never invoke it. Only e2e_dojo.yml
actually needs uv (the dojo scripts use uv sync/run for Python agents).
Removing the unnecessary step saves CI time and reduces confusion.
Parallel CI workflows were each getting a different Nx Cloud execution
ID, resulting in separate CIPEs instead of one unified view. Set a
stable NX_CI_EXECUTION_ID env var using head_ref + sha + run_attempt
so all workflows for the same push are grouped together. Also add
NX_CI_EXECUTION_ENV per workflow to create labeled tab sections in the
Nx Cloud CIPE page.