chore: Update the run-test-service.sh script for new package names. (#1251)

<!-- CURSOR_SUMMARY -->
> [!NOTE]
> **Low Risk**
> Low risk change limited to a contract-test shell script; main impact
is ensuring CI/dev test runs still find the correct Yarn workspace.
> 
> **Overview**
> Updates `packages/sdk/browser/contract-tests/run-test-service.sh` to
run the contract test service using the new scoped Yarn workspace name
(`@launchdarkly/browser-contract-test-service`) for both the adapter and
main service commands.
> 
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Author: kinyoklion

packages/sdk/browser/contract-tests/run-test-service.sh

@@ -1 +1 @@
-yarn workspace browser-contract-test-service run start:adapter & yarn workspace browser-contract-test-service run start && kill $!
+yarn workspace @launchdarkly/browser-contract-test-service run start:adapter & yarn workspace @launchdarkly/browser-contract-test-service run start && kill $!