Backport of Fix Exec not working with reverse proxy X-Nomad-Token into release/1.3.x

[hc-github-team-nomad-core]

Backport

This PR is auto-generated from #12925 to be assessed for backporting due to the inclusion of the label backport/1.3.x.

The below text is copied from the body of the original PR.

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This fixes an issue with Exec feature not working when a reverse proxy is used to automatically inject X-Nomad-Token.

[github-actions]

Ember Asset Size action

As of bc082ab

Files that got Bigger 🚨:

File	raw	gzip
nomad-ui.js	+29 B	+16 B

Files that stayed the same size 🤷‍:

File	raw	gzip
vendor.js	0 B	0 B
nomad-ui.css	0 B	0 B
vendor.css	0 B	0 B

[github-actions]

Ember Test Audit comparison

	release/1.3.x	bc082ab	change
passes	1286	1287	+1
failures	2	2	0
flaky	1	0	-1
duration	000ms	000ms	-000ms

[github-actions]

Ember Test Audit flaky tests

Ember Test Audit detected these flaky tests on release/1.3.x:

• Acceptance | optimize: lets recommendations be toggled, reports the choices to the recommendations API, and displays task group recommendations serially

[github-actions]

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