Remove empty RTS

Author: joaopsazevedo

testsuite/ada_lsp/refactoring_imports_commands/U511-009.refactoring.import_with_use/default.gpr

@@ -1,4 +1,3 @@
 project Default is
    for Main use ("foo.adb");
-   for Runtime ("Ada") use "./rts-empty";
 end Default;

testsuite/ada_lsp/refactoring_imports_commands/U511-009.refactoring.import_with_use/rts-empty/adainclude/ada.ads

@@ -1,4 +1,3 @@
 project Default is
    for Main use ("main.adb");
-   for Runtime ("Ada") use "./rts-empty";
 end Default;

testsuite/ada_lsp/refactoring_imports_commands/U511-009.refactoring.import_with_use/rts-empty/adainclude/system.ads

@@ -1,4 +1,3 @@
 project Default is
    for Main use ("main.adb");
-   for Runtime ("Ada") use "./rts-empty";
 end Default;