ci: Fix docs nightlies potentially running some examples against latest

docs/snapshotter/docker/python/docker-compose.numba.yml

@@ -2,6 +2,7 @@ services:
   # Build the server image with NumPy pinned below 2.5 so the Numba examples
   # can import and run (Numba does not support NumPy 2.5).
   server:
+    image: deephaven-server-numba
     build:
       context: .
       dockerfile: ./numba.Dockerfile

docs/snapshotter/docker/python/docker-compose.pyclient.yml

@@ -7,10 +7,13 @@ services:
       dockerfile: ./pyclient.Dockerfile
       no_cache: true
       target: pypi-version
+      args:
+        - DEEPHAVEN_SERVER_IMAGE=${DEEPHAVEN_SERVER_IMAGE}
   # This is the server the snapshot tool uses
   # It is really used to run the pydeephaven client from the server Python environment
   server:
-    build: 
+    image: deephaven-server-pyclient
+    build:
       context: .
       dockerfile: ./pyclient.Dockerfile # Installs pydeephaven to the server
       target: server

docs/snapshotter/docker/python/numba.Dockerfile

@@ -1,4 +1,5 @@
-ARG DEEPHAVEN_SERVER_IMAGE=ghcr.io/deephaven/server:latest
+# check InvalidDefaultArgInFrom=skip
+ARG DEEPHAVEN_SERVER_IMAGE
 FROM ${DEEPHAVEN_SERVER_IMAGE}
 
 # Numba does not yet support NumPy 2.5, but the base server image ships NumPy 2.5.

docs/snapshotter/docker/python/pyclient.Dockerfile

@@ -1,7 +1,8 @@
+# check=skip=InvalidDefaultArgInFrom
 # Should be run with --no-cache to ensure the latest pydeephaven is installed
 # This arg must go first otherwise Docker thinks it is part of pypi-version
 # if it is above the server FROM line
-ARG DEEPHAVEN_SERVER_IMAGE=ghcr.io/deephaven/server:latest
+ARG DEEPHAVEN_SERVER_IMAGE
 FROM alpine/curl AS pypi-version
 WORKDIR /src
 RUN curl https://pypi.org/pypi/pydeephaven/json > ./plugin-version.json