Display a warning for using option --ignore-stdin when request fails with content present in stdin

[landure]

Checklist

• [ X] I've searched for similar issues.
• [ X] I'm using the latest version of HTTPie.

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Running environment

• Ubuntu 22.04.3 LTS Jammy
• bash 5.1-6ubuntu1
• HTTPie 3.2.1 from https://packages.httpie.io/deb
• jq (jq @ GitHub) 1.6-2.1ubuntu3.

Minimal reproduction code and steps

Install the software:

sudo apt install 'miller' jq'

The error occurred when interrogating Gandi Public API.

Set Gandi API Key:

gandi_api_key="<Gandi API key>"

Query Gandi API for all domains mailboxes:

while read -r 'domain'; do
  command https --body "https://api.gandi.net/v5/email/mailboxes/${domain}" \
    "Authorization: Apikey ${gandi_api_key}" 'per_page==250'
done < <( command https --body 'https://api.gandi.net/v5/domain/domains' \
    "Authorization: Apikey ${gandi_api_key}" 'per_page==250' |
  command jq '.[].fqdn' |
  command tr --delete '"' )

Current result

The first loop output is:

Bad Request

Expected result

The expected result:

Bad Request

Warning: stdin contents detected. Retry with --ignore-stdin option.

Additional information, screenshots, or code examples

I've found the final answer in #1017 and when using --debug option. HTTPie should be able to detect if stdin contents come from a pipe or are for xargs or a bash loop. In any case, displaying a warning when a request fails with stdin content could prevent users some headaches.