[4.4] replace deprecated access of input property

[heelc29]

Summary of Changes

As directly access the input variable is deprecated since Joomla 4.0 in #28313, the core should not use it anymore. This pr changes the call to the getInput function.

Missed by PR #39029

Testing Instructions

Open backend

Actual result BEFORE applying this Pull Request

Use of deprecated access to the application's input property

Expected result AFTER applying this Pull Request

All works like before, but without using deprecated access to the application's input property

Link to documentations

Please select:

• No documentation changes for docs.joomla.org needed
• No documentation changes for manual.joomla.org needed

[alikon]

I have tested this item ✅ successfully on 7ba9127

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[richard67]

@heelc29 Could you fix this one, too? https://github.com/joomla/joomla-cms/blob/4.4-dev/administrator/modules/mod_guidedtours/tmpl/default.php#L30

[heelc29]

@richard67 Check out #40305

[richard67]

I have tested this item ✅ successfully on 4ee9f72

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[richard67]

RTC

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[MacJoom]

Thank you!