Add default overrides and unambiguous way of disabling them

docker-compose.overrides.yml

@@ -0,0 +1,4 @@
+services:
+  es:
+    # Memory limit for ES, as it tends to be a memory hoarder
+    mem_limit: 4294967296

justfile

@@ -7,6 +7,7 @@ set dotenv-load := false
 IS_PROD := env_var_or_default("PROD", "")
 IS_CI := env_var_or_default("CI", "")
 DC_USER := env_var_or_default("DC_USER", "opener")
+ENABLE_DC_OVERRIDES := env_var_or_default("OPENVERSE_ENABLE_DC_OVERRIDES", "true")
 
 # Show all available recipes, also recurses inside nested justfiles
 @_default:
@@ -103,6 +104,9 @@ env:
 DOCKER_FILE := "-f " + (
     if IS_PROD == "true" { "ingestion_server/docker-compose.yml" }
     else { "docker-compose.yml" }
+) + (
+    if ENABLE_DC_OVERRIDES == "true" { " -f docker-compose.overrides.yml" }
+    else { "" }
 )
 
 # Run `docker-compose` configured with the correct files and environment