[DOCS] Remove invalid configuration option from SMTP upgrade example

The example value '-t -i' for `transport_sendmail_command` is incorrect,
as an executable is expected to be provided, not just command flags.
Since this option is not needed for SMTP at all, it is dropped from this
example.

Releases: main, 12.4, 11.5
Resolves: #102837
Change-Id: I99569f23339ae68077edf16aaa59873aa84ba24d
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/82476


Tested-by: core-ci <typo3@b13.com>
Tested-by: Benjamin Franzke <ben@bnf.dev>
Reviewed-by: Benjamin Franzke <ben@bnf.dev>

typo3/sysext/core/Documentation/Changelog/11.5.x/Important-93635-AddMailConfigurationForSettingSmtpDomain.rst

@@ -30,7 +30,6 @@ Configuration Example for GSuite.
             'defaultMailFromAddress' => 'webserver@example.com',
             'defaultMailFromName' => 'SYSTEMMAIL',
             'transport' => 'smtp',
-            'transport_sendmail_command' => ' -t -i ',
             'transport_smtp_domain' => 'example.com',
             'transport_smtp_encrypt' => '',
             'transport_smtp_password' => '',