chore(deps): Update stable-baselines3 requirement

Updates the requirements on [stable-baselines3](https://github.com/DLR-RM/stable-baselines3) to permit the latest version.
- [Release notes](https://github.com/DLR-RM/stable-baselines3/releases)
- [Commits](https://github.com/DLR-RM/stable-baselines3/compare/v2.8.0...v2.9.0)

---
updated-dependencies:
- dependency-name: stable-baselines3
  dependency-version: 2.9.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/ci.yml

@@ -27,7 +27,7 @@ jobs:
     steps:
       - uses: actions/checkout@v6
 
-      - uses: actions/setup-python@v7
+      - uses: actions/setup-python@v6
         with:
           python-version: "3.10"
           cache: "pip"

.github/workflows/docs.yml

@@ -28,7 +28,7 @@ jobs:
       uses: actions/checkout@v6
 
     - name: Set up Python
-      uses: actions/setup-python@v7
+      uses: actions/setup-python@v6
       with:
         python-version: "3.10"
 

.github/workflows/lint.yml

@@ -19,7 +19,7 @@ jobs:
       uses: actions/checkout@v6
 
     - name: Set up Python
-      uses: actions/setup-python@v7
+      uses: actions/setup-python@v6
       with:
         python-version: "3.10"
 

.github/workflows/scheduled-tests.yml

@@ -21,7 +21,7 @@ jobs:
     steps:
       - uses: actions/checkout@v6
 
-      - uses: actions/setup-python@v7
+      - uses: actions/setup-python@v6
         with:
           python-version: ${{ matrix.python-version }}
           cache: "pip"
@@ -51,7 +51,7 @@ jobs:
     steps:
       - uses: actions/checkout@v6
 
-      - uses: actions/setup-python@v7
+      - uses: actions/setup-python@v6
         with:
           python-version: "3.10"
           cache: "pip"

.github/workflows/security.yml

@@ -22,7 +22,7 @@ jobs:
       uses: actions/checkout@v6
 
     - name: Set up Python
-      uses: actions/setup-python@v7
+      uses: actions/setup-python@v6
       with:
         python-version: "3.10"
 

requirements/rl.txt

@@ -8,7 +8,7 @@
 # Only install if you want to use full PPO/A2C/SAC training.
 
 # Core RL library
-stable-baselines3[extra]>=2.8.0
+stable-baselines3[extra]>=2.9.0
 
 # Gymnasium environment (OpenAI Gym successor)
 gymnasium>=0.29.1