Update Dockerfile

Dockerfile

@@ -5,13 +5,16 @@ ENV DEBIAN_FRONTEND=noninteractive \
     HOME=/home/user \
     PATH=/home/user/.local/bin:$PATH
 
-# Install Git, Python 3.9, and required packages
+# Add the deadsnakes PPA for Python 3.9
 RUN apt-get update && \
+    apt-get install -y software-properties-common && \
+    add-apt-repository ppa:deadsnakes/ppa && \
+    apt-get update && \
     apt-get install -y git python3.9 python3.9-dev python3-pip wget libgl1-mesa-glx && \
     apt-get clean && \
     rm -rf /var/lib/apt/lists/* && \
     wget https://bootstrap.pypa.io/get-pip.py && \
-    python3.9 get-pip.py && \ 
+    python3.9 get-pip.py && \
     rm get-pip.py
     
 # Set up a new user named "user" with user ID 1000