fix: reduce size of container

.devcontainer/Dockerfile

@@ -1,5 +1 @@
 FROM python:3.12
-
-# Install python requirements
-COPY backend/requirements-combined.txt requirements-combined.txt
-RUN pip install -r requirements-combined.txt

.devcontainer/devcontainer.json

@@ -2,7 +2,7 @@
   "name": "retro_olympics",
   "dockerComposeFile": "docker-compose.yml",
   "service": "webapp",
-  "workspaceFolder": "/workspace",
+  "workspaceFolder": "/workspaces/${localWorkspaceFolderBasename}",
   "features": {
     "ghcr.io/devcontainers/features/node:1": {
       "nodeGypDependencies": true,
@@ -23,6 +23,7 @@
   },
   "remoteUser": "root",
   "remoteEnv": {
-    "PYTHONPATH": "/workspace/backend/src"
-  }
+    "PYTHONPATH": "/workspaces/${localWorkspaceFolderBasename}/backend/src"
+  },
+  "postCreateCommand": "cd backend/ && pip install -r requirements-combined.txt"
 }

.devcontainer/docker-compose.yml

@@ -3,11 +3,11 @@ version: "3.8"
 services:
   webapp:
     build:
-      context: ..
-      dockerfile: .devcontainer/Dockerfile
+      context: .
+      dockerfile: Dockerfile
     entrypoint: ["tail", "-f", "/dev/null"]
     volumes:
-      - ..:/workspace
+      - ../..:/workspaces:cached
     command: sleep infinity
     network_mode: service:db
   db: