docker: don't run executable as root (#378)

The image now runs with user and group 248, which is just a random number, no user or group with that ID exist by default.

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Co-authored-by: The King of Half-Baked Projects <[email protected]>

Author: Bixilon

fly.Dockerfile

@@ -36,3 +36,5 @@ COPY --from=builder /app/scribblers /scribblers
 COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
 
 ENTRYPOINT ["/scribblers"]
+# Random uid to avoid having root privileges. Linux doesn't care that there's no user for it.
+USER 248:248

linux.Dockerfile

@@ -33,3 +33,5 @@ COPY --from=builder /app/scribblers /scribblers
 COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
 
 ENTRYPOINT ["/scribblers"]
+# Random uid to avoid having root privileges. Linux doesn't care that there's no user for it.
+USER 248:248