[release/7.0-rc2] Use determinism instead of timing in cancellation tests#75655

carlossanlop merged 3 commits intorelease/7.0-rc2dotnet/runtime:release/7.0-rc2from

backport/pr-75623-to-release/7.0-rc2dotnet/runtime:backport/pr-75623-to-release/7.0-rc2Copy head branch name to clipboard