Fixes typos in render interval warning messages (#1237)

# Description

Fixes typos in render interval warning messages

## Type of change

- Bug fix (non-breaking change which fixes an issue)

## Checklist

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./isaaclab.sh --format`
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [ ] I have updated the changelog and the corresponding version in the
extension's `config/extension.toml` file
- [x] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there

source/extensions/omni.isaac.lab/omni/isaac/lab/envs/direct_marl_env.py

@@ -102,7 +102,7 @@ class DirectMARLEnv:
         if self.cfg.sim.render_interval < self.cfg.decimation:
             msg = (
                 f"The render interval ({self.cfg.sim.render_interval}) is smaller than the decimation "
-                f"({self.cfg.decimation}). Multiple multiple render calls will happen for each environment step."
+                f"({self.cfg.decimation}). Multiple render calls will happen for each environment step."
                 "If this is not intended, set the render interval to be equal to the decimation."
             )
             omni.log.warn(msg)

source/extensions/omni.isaac.lab/omni/isaac/lab/envs/direct_rl_env.py

@@ -107,7 +107,7 @@ class DirectRLEnv(gym.Env):
         if self.cfg.sim.render_interval < self.cfg.decimation:
             msg = (
                 f"The render interval ({self.cfg.sim.render_interval}) is smaller than the decimation "
-                f"({self.cfg.decimation}). Multiple multiple render calls will happen for each environment step."
+                f"({self.cfg.decimation}). Multiple render calls will happen for each environment step."
                 "If this is not intended, set the render interval to be equal to the decimation."
             )
             omni.log.warn(msg)

source/extensions/omni.isaac.lab/omni/isaac/lab/envs/manager_based_env.py

@@ -103,7 +103,7 @@ class ManagerBasedEnv:
         if self.cfg.sim.render_interval < self.cfg.decimation:
             msg = (
                 f"The render interval ({self.cfg.sim.render_interval}) is smaller than the decimation "
-                f"({self.cfg.decimation}). Multiple multiple render calls will happen for each environment step. "
+                f"({self.cfg.decimation}). Multiple render calls will happen for each environment step. "
                 "If this is not intended, set the render interval to be equal to the decimation."
             )
             omni.log.warn(msg)