Remove linkerJS altogether because it is too flaky on the CI.

Most tests require loading the `fulllib`, which seems to be too
much for the CI environment in many cases.

Author: sjrd

run.sh

@@ -13,7 +13,7 @@ echo "Scala.js branch: $SCALAJS_BRANCH"
 
 case $SCALAJS_BRANCH in
   main)
-    TESTS="helloworld$SUFFIX/run testSuite$SUFFIX/test testSuiteJVM$SUFFIX/test ir$SUFFIX/test irJS$SUFFIX/test set~linker.v$SUFFIX/Test/testOptions+=Tests.Filter(_!="'"'"org.scalajs.linker.BackwardsCompatTest"'"'");linker$SUFFIX/testOnly~--~-v set~linkerJS.v$SUFFIX/Test/testOptions+=Tests.Filter(_!="'"'"org.scalajs.linker.BackwardsCompatTest"'"'");linkerJS$SUFFIX/testOnly~--~-v"
+    TESTS="helloworld$SUFFIX/run testSuite$SUFFIX/test testSuiteJVM$SUFFIX/test ir$SUFFIX/test irJS$SUFFIX/test set~linker.v$SUFFIX/Test/testOptions+=Tests.Filter(_!="'"'"org.scalajs.linker.BackwardsCompatTest"'"'");linker$SUFFIX/testOnly~--~-v"
     ;;
   *)
     echo "Unknown Scala.js branch $SCALAJS_BRANCH"