Completely remove the testGroup events

This was done because they were 1:1 mapping to testRun events, and
I could not think of a reasonable way to make them their own thing.

tests/SelfTest/Baselines/junit.sw.approved.txt

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <testsuitesloose text artifact
 >
-  <testsuite name="<exe-name>" errors="17" failures="130" tests="2121" hostname="tbd" time="{duration}" timestamp="{iso8601-timestamp}">
+  <testsuite name="<exe-name>" errors="17" failures="129" tests="2120" hostname="tbd" time="{duration}" timestamp="{iso8601-timestamp}">
     <properties>
       <property name="filters" value="~[!nonportable]~[!benchmark]~[approvals] *"/>
       <property name="random-seed" value="1"/>