revert: these 2 settings (#11906)

Signed-off-by: -LAN- <laipz8200@outlook.com>
Co-authored-by: -LAN- <laipz8200@outlook.com>

docker/.env.example

 # Maximum number of submitted thread count in a ThreadPool for parallel node execution
 MAX_SUBMIT_COUNT=100
 
-# Proxy
-HTTP_PROXY=
-HTTPS_PROXY=

docker/docker-compose.yaml

   CSP_WHITELIST: ${CSP_WHITELIST:-}
   CREATE_TIDB_SERVICE_JOB_ENABLED: ${CREATE_TIDB_SERVICE_JOB_ENABLED:-false}
   MAX_SUBMIT_COUNT: ${MAX_SUBMIT_COUNT:-100}
-  HTTP_PROXY: ${HTTP_PROXY:-}
-  HTTPS_PROXY: ${HTTPS_PROXY:-}
 
 services:
   # API service