Move the disabling of Horizon state verification into horizon.env files (#813)

### What
Disable state verification for Horizon by setting
INGEST_DISABLE_STATE_VERIFICATION=True directly in horizon.env files for
both common and local configurations. Remove conditional logic from the
start script that previously set this variable only for local networks
or protocol versions above 19.

  ### Why
State verification is now disabled universally rather than
conditionally, simplifying configuration and ensuring consistent
behavior across all network types and protocol versions. The conditions
are practically true all the time anyway, since it is always set when
the protocol is greater than 19.

Author: leighmcculloch

common/horizon/etc/horizon.env

@@ -15,3 +15,4 @@ export HISTORY_ARCHIVE_URLS="__ARCHIVE__"
 export ADMIN_PORT=6060
 export PORT=8001
 export CHECKPOINT_FREQUENCY=64
+export INGEST_DISABLE_STATE_VERIFICATION=True

local/horizon/etc/horizon.env

@@ -15,3 +15,4 @@ export HISTORY_ARCHIVE_URLS="__ARCHIVE__"
 export ADMIN_PORT=6060
 export PORT=8001
 export CHECKPOINT_FREQUENCY=8
+export INGEST_DISABLE_STATE_VERIFICATION=True

start

@@ -531,12 +531,6 @@ EOF
 
   run_silent "chown-horizon" chown -R stellar:stellar .
 
-  if [[ "$NETWORK" = "local" || (".$PROTOCOL_VERSION" != ".none"  &&  $PROTOCOL_VERSION -gt 19) ]] ; then    
-    cat << EOF >> etc/horizon.env
-export INGEST_DISABLE_STATE_VERIFICATION=True
-EOF
-  fi
-
   start_postgres
   run_silent "init-horizon-db" sudo -u stellar ./bin/horizon db init
   touch .quickstart-initialized