Update Dockerfile

Dockerfile

@@ -1,7 +1,7 @@
 # syntax=docker/dockerfile:1
-FROM sebmilardo/py-osrm-socal:24.06
+FROM sebmilardo/py-osrm-socal@sha256:8a321b8d2459dacff90df7d1217ed25efecb451e6eeb90d6727b9e217a6e29a0
 ENV PATH="/venv/bin:$PATH"
 
 COPY requirements.txt requirements.txt
 
-RUN pip install --upgrade pip && pip install -r requirements.txt
+RUN pip install --upgrade pip && pip install -r requirements.txt