"Delete" button on environment's detail page does nothing

Summary

Delete button on the individual environment detail page does not delete. Clicking on it leads to nothing.

Steps to reproduce

Open any environment from the list of the environments: Operations > Environments.
Ensure that environment is stopped.
Click Delete button.
Nothing happens.

Example Project

https://gitlab.com/dmitry-udio/delete-environment-bug/-/environments/6407935

(As a note on Firefox there are no "Edit" and "Delete" buttons visible at all, but on Chrome and Safari there are buttons, and Edit works, but Delete does not).

What is the current bug behavior?

Nothing happens when you press "Delete" button.

What is the expected correct behavior?

Delete Confirmation dialog should open after clicking on "Delete" button.

Relevant logs and/or screenshots

Expand to see the screenshot of the relevant page

Output of checks

Results of GitLab environment info

Expand for output related to GitLab environment info

System information
System:         Ubuntu 16.04
Proxy:          no
Current User:   git
Using RVM:      no
Ruby Version:   2.7.2p137
Gem Version:    3.1.4
Bundler Version:2.1.4
Rake Version:   13.0.3
Redis Version:  6.0.14
Git Version:    2.31.1
Sidekiq Version:5.2.9
Go Version:     unknown

GitLab information
Version:        13.12.8-ee
Revision:       6ab58f00404
Directory:      /opt/gitlab/embedded/service/gitlab-rails
DB Adapter:     PostgreSQL
DB Version:     12.6
URL:            https://gitlab.ud.io
HTTP Clone URL: https://gitlab.ud.io/some-group/some-project.git
SSH Clone URL:  git@gitlab.ud.io:some-group/some-project.git
Elasticsearch:  no
Geo:            no
Using LDAP:     no
Using Omniauth: yes
Omniauth Providers: gitlab

GitLab Shell
Version:        13.18.0
Repository storage paths:
- default:      /var/opt/gitlab/git-data/repositories
GitLab Shell path:              /opt/gitlab/embedded/service/gitlab-shell
Git:            /opt/gitlab/embedded/bin/git

Results of GitLab application Check

Expand for output related to the GitLab application check

Checking GitLab subtasks ...
Checking GitLab Shell ...
GitLab Shell: ... GitLab Shell version >= 13.18.0 ? ... OK (13.18.0)
Running /opt/gitlab/embedded/service/gitlab-shell/bin/check
Internal API available: OK
Redis available via internal API: OK
gitlab-shell self-check successful
Checking GitLab Shell ... Finished
Checking Gitaly ...
Gitaly: ... default ... OK
Checking Gitaly ... Finished
Checking Sidekiq ...
Sidekiq: ... Running? ... yes
Number of Sidekiq processes (cluster/worker) ... 1/1
Checking Sidekiq ... Finished
Checking Incoming Email ...
Incoming Email: ... Reply by email is disabled in config/gitlab.yml
Checking Incoming Email ... Finished
Checking LDAP ...
LDAP: ... LDAP is disabled in config/gitlab.yml
Checking LDAP ... Finished
Checking GitLab App ...
Git configured correctly? ... yes
Database config exists? ... yes
All migrations up? ... yes
Database contains orphaned GroupMembers? ... no
GitLab config exists? ... yes
GitLab config up to date? ... yes
Log directory writable? ... yes
Tmp directory writable? ... yes
Uploads directory exists? ... yes
Uploads directory has correct permissions? ... yes
Uploads directory tmp has correct permissions? ... yes
Init script exists? ... skipped (omnibus-gitlab has no init script)
Init script up-to-date? ... skipped (omnibus-gitlab has no init script)
Projects have namespace: ...
3/1 ... yes
3/2 ... yes
5/3 ... yes
3/4 ... yes
3/5 ... yes
3/6 ... yes
3/7 ... yes
6/8 ... yes
5/10 ... yes
5/11 ... yes
5/12 ... yes
5/13 ... yes
5/14 ... yes
5/15 ... yes
5/16 ... yes
5/17 ... yes
5/18 ... yes
5/19 ... yes
5/20 ... yes
5/21 ... yes
5/22 ... yes
5/23 ... yes
5/24 ... yes
5/25 ... yes
5/26 ... yes
5/27 ... yes
5/28 ... yes
2/29 ... yes
6/34 ... yes
6/35 ... yes
6/36 ... yes
Redis version >= 5.0.0? ... yes
Ruby version >= 2.7.2 ? ... yes (2.7.2)
Git version >= 2.31.0 ? ... yes (2.31.1)
Git user has default SSH configuration? ... yes
Active users: ... 2
Is authorized keys file accessible? ... yes
GitLab configured to store new projects in hashed storage? ... yes
All projects are in hashed storage? ... yes
Elasticsearch version 7.x (6.4 - 6.x deprecated to be removed in 13.8)? ... skipped (elasticsearch is disabled)
Checking GitLab App ... Finished
Checking GitLab subtasks ... Finished

Possible fixes