Base prelease build stage on base instead of on install (#7289)

There is no reason to have the entire install stage for the
prerelease stage. Instead use the base as base and copy
in the relevent files (which already happened)

docs/guides/ecosystem/docker.md

@@ -32,7 +32,7 @@ RUN cd /temp/prod && bun install --frozen-lockfile --production
 
 # copy node_modules from temp directory
 # then copy all (non-ignored) project files into the image
-FROM install AS prerelease
+FROM base AS prerelease
 COPY --from=install /temp/dev/node_modules node_modules
 COPY . .