Purging jobs not working consistently between methods

### Nomad version
1.5.6

### Operating system and Environment details
Ubuntu 22.04

### Issue
Purging a job is not working consistently when using the CLI and Web UI. There's also a difference when purging jobs within a namespace with a namespace specific token.

### Reproduction steps
1. sudo nomad agent -dev -acl-enabled
2. nomad acl bootstrap
3. export NOMAD_TOKEN=
4. nomad namespace apply app1
5. Create policy file policy-app1.hcl:
`namespace "app1" { policy = "write" }`
6. nomad acl policy apply app1 policy-app1.hcl
7. nomad acl token create -name "app1" -policy app1
8. nomad job init
9. NOMAD_TOKEN= NOMAD_NAMESPACE=app1 nomad job run example.nomad.hcl

#### Expected Result
Whatever method I use to purge a job, it should not show up in the Web UI or job list after purging, nor should I get an ACL error when I purge a job in a namespace when that token has `policy = "write"` or `submit-job` in it.

#### Actual Result
There are 3 different outcomes:

##### 1. Purge via CLI with app1 token
You run `NOMAD_TOKEN= NOMAD_NAMESPACE=app1 nomad job stop -purge example` and the job is stopped, purged and does not show up in the Web UI. All good, no errors.

##### 2. Purge via Web UI with app1 token
1. NOMAD_TOKEN= nomad ui -authenticate
2. Go to: http://127.0.0.1:4646/ui/jobs/example@app1
3. Click on: "Stop Job", "Yes, Stop Job", "Purge Job", "Yes, Purge Job".

Result: Error purging job
Your ACL token does not grant permission to purge jobs.
Job is shown "Dead" in Web UI.

##### 3. Purge via Web UI with management token
1. nomad ui -authenticate
2. Go to: http://127.0.0.1:4646/ui/jobs/example@app1
3. Click on: "Stop Job", "Yes, Stop Job", "Purge Job", "Yes, Purge Job".

Result: No ACL error. Job is shown "Dead" in Web UI, not purged.

### Job file
You can use the example one that nomad gives you with `nomad job init`.

### Nomad Server logs
(When pressing "Yes, Purge Job" with app1 token)
2023-05-31T12:08:24.368+0200 [DEBUG] http: request failed: method=DELETE path=/v1/job/example?namespace=app1?purge=true error="Permission denied" code=403

(When pressing "Yes, Purge Job" with management token)
2023-05-31T12:11:49.952+0200 [DEBUG] http: request complete: method=DELETE path=/v1/job/example?namespace=app1?purge=true duration="386.888µs"

### Additional info
I can see the correct `X-Nomad-Token` being send with the purge request.