chore: Revert changes to Dockerfile

Dockerfile

@@ -13,11 +13,10 @@ RUN apt-get update && \
     rm -rf /var/lib/apt/lists/*
 
 # Include global arg in this stage of the build
-ARG FUNCTION_DIR="/var/task"
+ARG FUNCTION_DIR
 
 # Create function directory
 RUN mkdir -p ${FUNCTION_DIR}
-# Set working directory to function root directory
 WORKDIR ${FUNCTION_DIR}
 
 # Install the runtime interface client
@@ -31,7 +30,6 @@ FROM mcr.microsoft.com/playwright/python:v1.43.0-jammy
 
 # Include global arg in this stage of the build
 ARG FUNCTION_DIR
-
 # Set working directory to function root directory
 WORKDIR ${FUNCTION_DIR}