Fix getPackageName which didn't respect "build ignore" (#7034)

This fixed the indexing problem caused by retrieving the wrong package name.

fixes #7010

golang/src/com/google/idea/blaze/golang/resolve/BlazeGoPackage.java

@@ -272,6 +272,7 @@ private static String getPackageName(Project project, Collection<File> files, St
         .map(psiManager::findFile)
         .filter(GoFile.class::isInstance)
         .map(GoFile.class::cast)
+        .filter(goFile -> !Objects.equals(goFile.getBuildFlags(), "ignore"))
         .map(GoFile::getCanonicalPackageName) // strips _test suffix from test packages
         .filter(Objects::nonNull)
         .findFirst() // short circuit