docs(cli-client/skill): use the real requests command in heal diagnose step

The heal section's diagnose snippet listed `playwright-cli network`, which
is not a command. Inspecting network traffic is done with `requests`, as
the DevTools examples in SKILL.md already show.

Author: adityasingh2400

packages/playwright-core/src/tools/cli-client/skill/references/spec-driven-testing.md

@@ -261,7 +261,7 @@ The test is paused at the start. Step forward or run to until just before the fa
 ```bash
 playwright-cli snapshot                # did the element change / move / rename?
 playwright-cli console                 # app-side errors?
-playwright-cli network                 # failed request? wrong payload?
+playwright-cli requests                # failed request? wrong payload?
 playwright-cli show --annotate         # ask the user to point somewhere
 ```