docs: V8 is a JavaScript engine, not a runtime (#7619)

docs/testing.md

@@ -212,7 +212,7 @@ Deno will automatically determine test coverage for your code if you specify the
 line basis for modules that share the parent directory with at-least one test
 module that is being executed.
 
-This coverage information is acquired directly from the JavaScript runtime (V8).
+This coverage information is acquired directly from the JavaScript engine (V8).
 Because of this, the coverage reports are very accurate.
 
 When all tests are done running a summary of coverage per file is printed to