Don't set a pre-build memory limit

Trying to fix https://jupyter.zulipchat.com/#narrow/channel/469744-jupyterhub/topic/try.20mybinder.20jupyterleab.20demo.20broken,
which is breaking because mamba gets OOM killed. We have memory limits
set on dind as a whole, and memory_limit for builds (in its current,
per-build form) is going away as part of jupyterhub/repo2docker#1402
as well. So let's remove it and see.

config/hetzner-2i2c-bare.yaml

@@ -40,7 +40,6 @@ binderhub:
     # complicated: dind memory request + KubernetesBuildExecutor.memory_request * builds_per_node ~= node memory
     KubernetesBuildExecutor:
       memory_request: "2G"
-      memory_limit: "4G"
       docker_host: /var/run/dind/docker.sock
       repo2docker_extra_args:
         # try to avoid timeout pushing to local registry

config/hetzner-2i2c.yaml

@@ -40,7 +40,6 @@ binderhub:
     # complicated: dind memory request + KubernetesBuildExecutor.memory_request * builds_per_node ~= node memory
     KubernetesBuildExecutor:
       memory_request: "2G"
-      memory_limit: "4G"
       docker_host: /var/run/dind/docker.sock
       repo2docker_extra_args:
         # try to avoid timeout pushing to local registry

config/staging.yaml

@@ -10,7 +10,6 @@ binderhub:
       badge_base_url: https://staging.mybinder.org
       image_prefix: us-central1-docker.pkg.dev/binderhub-288415/staging/r2d-2023-04-
       sticky_builds: true
-      build_memory_limit: "2G"
     DockerRegistry:
       token_url: "https://us-central1-docker.pkg.dev/v2/token"
 

mybinder/values.yaml

@@ -218,7 +218,6 @@ binderhub:
           }
     KubernetesBuildExecutor:
       build_image: quay.io/jupyterhub/repo2docker:2024.07.0-68.gdd097a2
-      memory_limit: "3G"
       memory_request: "1G"
 
   extraConfig: