[submitters] Fix os.path.join for rez binary

Removing the "/" of "bin/rez" allows the `join` to work effectively.
If it is kept, `rezBin` is erroneously set to `/bin/rez`.

Author: cbentejac

meshroom/submitters/tractorSubmitter.py

@@ -103,7 +103,7 @@ def rezWrapCommand(cmd, useCurrentContext: bool = True, otherRezPkg: list[str] =
         if "REZ_BIN" in os.environ:
             rezBin = os.environ["REZ_BIN"]
         elif "REZ_PACKAGES_ROOT" in os.environ:
-            rezBin = os.path.join(os.environ["REZ_PACKAGES_ROOT"], "/bin/rez")
+            rezBin = os.path.join(os.environ["REZ_PACKAGES_ROOT"], "bin/rez")
         return f"{rezBin} env {packagesStr} -- {cmd}"
     return cmd