Cleanup of old issues and PRs

[cyrgani]

This is an issue to list old issues and PRs that should have been closed or merged a long time ago, because the thing they are trying to fix no longer exists or was fixed already elsewhere. I will update it whenever I see another obsolete item.

Obsolete PRs that should be closed

• Let anyone get the DPI scale #609: this feature exists already, as macroquad::window::screen_dpi_scale()
• Fix constant sample_count #42: the sample_count is no longer set to 4 anywhere
• A simple missile command game clone from 80s Atari. #536 and Fix for CI fmt fix error #537: both contain the same code, at least one should be closed
• Fix 'attempt to add with overflow' in draw_poly #493: this no longer overflows with sides = 255 since 0..=sides is used instead of 0..sides + 1
• add measure_multiline_text #884: rebased and merged in Measure Multiline Text #993

Issues that were already fixed or no longer apply

• Change Edition to "2021" in Cargo.toml #323: the crate already uses edition 2021
• measure_text returns wrong (way too low) values #373: this was already fixed by Fix: incorrect text dimensions from measure_text on custom dpi #407, but not closed afterwards
• [Feature Request] Ellipses #575: this was alread fixed by draw_ellipse and draw_ellipse_lines #668
• Version bump using latest quad-snd #480: version was already bumped
• Drawing to the second render target created on the same frame results in a white texture #875: was already fixed on master, 0.4.14 has been released since then which includes the fix
• no measure_multiline_text()? #870: implemented in Measure Multiline Text #993