remove code to delete Gemfile.lock

we no longer need to remove the Gemfile.lock, remove the code that
does this as part of setup.

Test Plan:
- Jenkins docker smoke passes
- running docker_dev_setup.sh locally passes

Change-Id: Ic8807497f0f7489028ae474f0774cc5f871cb0f9
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/311951
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: Andrea Cirulli <andrea.cirulli@instructure.com>
Build-Review: Andrea Cirulli <andrea.cirulli@instructure.com>
QA-Review: James Butters <jbutters@instructure.com>
Product-Review: James Butters <jbutters@instructure.com>

Jenkinsfile.docker-smoke

@@ -82,7 +82,6 @@ EOF
                 source script/common/canvas/build_helpers.sh
 
                 build_images
-                check_gemfile
                 docker_compose_up
                 build_assets
               '''

script/common/canvas/build_helpers.sh

@@ -32,25 +32,6 @@ function build_images {
   stop_spinner
 }
 
-function check_gemfile {
-  if [[ -e Gemfile.lock ]]; then
-    message \
-'For historical reasons, the Canvas Gemfile.lock is not tracked by git. We may
-need to remove it before we can install gems, to prevent conflicting dependency
-errors.'
-    confirm_command 'rm -f Gemfile.lock' || true
-  fi
-
-  # Fixes 'error while trying to write to `/usr/src/app/Gemfile.lock`'
-  if ! _canvas_lms_track_with_log $DOCKER_COMMAND run --no-deps --rm web touch Gemfile.lock; then
-    message \
-"The 'docker' user is not allowed to write to Gemfile.lock. We need write
-permissions so we can install gems."
-    touch Gemfile.lock
-    confirm_command 'chmod a+rw Gemfile.lock' || true
-  fi
-}
-
 function build_assets {
   message "Building assets..."
   start_spinner "> Bundle install..."

script/docker_dev_setup.sh

@@ -36,7 +36,6 @@ copy_docker_config
 setup_docker_compose_override
 build_images
 docker_compose_up
-check_gemfile
 build_assets
 create_db
 display_next_steps