Fix run-benchmark --subtests arg for jetstream3.plan

[Achierius]

b2adc09

Fix run-benchmark `--subtests` arg for jetstream3.plan
https://bugs.webkit.org/show_bug.cgi?id=306290
rdar://168940723

Reviewed by Dewei Zhu.

Previously, the `test=` cmd was missing the & to separate it from the
previous `report=true` query param.

* Tools/Scripts/webkitpy/benchmark_runner/data/plans/jetstream3.plan: add '&'

Canonical link: https://commits.webkit.org/306245@main

6f28f21

Misc	iOS, visionOS, tvOS & watchOS	macOS	Linux	Windows	Apple Internal
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	🛠 win	⏳ 🛠 ios-apple
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2	🧪 win-tests	⏳ 🛠 mac-apple
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	🧪 api-mac	✅ 🧪 api-wpe		⏳ 🛠 vision-apple
✅ 🧪 webkitpy	🧪 ios-wk2-wpt	✅ 🧪 api-mac-debug	✅ 🛠 wpe-cairo-libwebrtc
	✅ 🧪 api-ios	✅ 🧪 mac-wk1	✅ 🛠 gtk
	🛠 vision	✅ 🧪 mac-wk2	✅ 🧪 gtk-wk2
	✅ 🛠 vision-sim	✅ 🧪 mac-AS-debug-wk2	✅ 🧪 api-gtk
✅ 🛠 🧪 merge	🧪 vision-wk2	✅ 🧪 mac-wk2-stress	🛠 playstation
	✅ 🛠 tv	🧪 mac-intel-wk2
	🛠 tv-sim
	🛠 watch
	✅ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on current version of this PR (hash 6f28f21)

Details

Misc	iOS, visionOS, tvOS & watchOS	macOS	Linux	Windows	Apple Internal
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	🛠 win	⏳ 🛠 ios-apple
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2	🧪 win-tests	⏳ 🛠 mac-apple
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	🧪 api-mac	✅ 🧪 api-wpe		⏳ 🛠 vision-apple
✅ 🧪 webkitpy	🧪 ios-wk2-wpt	✅ 🧪 api-mac-debug	✅ 🛠 wpe-cairo-libwebrtc
	✅ 🧪 api-ios	✅ 🧪 mac-wk1	✅ 🛠 gtk
	🛠 vision	✅ 🧪 mac-wk2	✅ 🧪 gtk-wk2
	✅ 🛠 vision-sim	✅ 🧪 mac-AS-debug-wk2	✅ 🧪 api-gtk
✅ 🛠 🧪 merge	🧪 vision-wk2	✅ 🧪 mac-wk2-stress	🛠 playstation
	✅ 🛠 tv	🧪 mac-intel-wk2
	🛠 tv-sim
	🛠 watch
	✅ 🛠 watch-sim

[dewei-zhu]

r=me

[webkit-commit-queue]

Committed 306245@main (b2adc09): https://commits.webkit.org/306245@main

Reviewed commits have been landed. Closing PR #57274 and removing active labels.