Update explicit-failures-markup.xml

[skip ci]

status/explicit-failures-markup.xml

@@ -3604,13 +3604,10 @@ for more information.
             <test name="issue0059"/>
             <test name="issue0061"/>
             <test name="propagate"/>
-            <toolset name="gcc-8-c++17"/>
-            <toolset name="gcc-8-c++2a"/>
-            <toolset name="gcc-8-gnu17"/>
-            <toolset name="gcc-8-gnu2a"/>
-            <toolset name="gcc-8-c++2a-O2"/>
-            <toolset name="gcc-8-c++2a-warn"/>
-            <toolset name="gcc-8~c++2a"/>
+            <toolset name="gcc-8~c++17"/>
+            <toolset name="gcc-8~c++2a*"/>
+            <toolset name="gcc-8~gnu17"/>
+            <toolset name="gcc-8~gnu2a"/>
             <toolset name="gcc-7~c++1z"/>
             <note author="Niall Douglas">GCC 8 currently ICEs with Outcome's unit tests in C++ 17 or later.</note>
         </mark-expected-failures>