gdb: unrecognized option `--return-child-result'
And we don't want to BDEP on egdb.

Index: tools/in-build-gimp.py
--- tools/in-build-gimp.py.orig
+++ tools/in-build-gimp.py
@@ -144,13 +144,7 @@ try:
 
   # Finally, run gimp!
   gimp_self = os.path.relpath(os.environ.get("GIMP_SELF_IN_BUILD"))
-  gimp_debug_self = os.environ.get("GIMP_DEBUG_SELF_WRAPPER")
-  if gimp_debug_self and "gdb" in gimp_debug_self and shutil.which("gdb"):
-    cmd = [gimp_debug_self,"--return-child-result","--batch","-x",f"{os.path.relpath(os.environ['GIMP_GLOBAL_SOURCE_ROOT'])}/tools/debug-in-build-gimp.py","--args", gimp_self] + sys.argv[1:]
-  elif gimp_debug_self and "lldb" in gimp_debug_self and shutil.which("lldb"):
-    cmd = [gimp_debug_self, "--batch", "-o", f"target create {gimp_self}", "-o", f"settings set -- target.run-args {' '.join(sys.argv[1:])}", "-o", f"script import importlib.util; spec = importlib.util.spec_from_file_location('debug_in_build_gimp', '{os.path.relpath(Path(os.environ['GIMP_GLOBAL_SOURCE_ROOT']))}/tools/debug-in-build-gimp.py'); m = importlib.util.module_from_spec(spec); spec.loader.exec_module(m)"]
-  else:
-    cmd = [gimp_self] + sys.argv[1:]
+  cmd = [gimp_self] + sys.argv[1:]
   sys.stderr.write(f"RUNNING: {shlex.join(cmd)}\n")
   subprocess.run(cmd, stdin=sys.stdin, check=True)
 
