Fix physics inconsistencies with different FPS

[alexobviously]

Currently on 30FPS you can jump twice as high as at 60FPS. In general, things behave strangely. Different friction etc.

Is this a forge bug? Are we not using forge right?

[alexobviously]

Notes:

• It seems like there are two 'modes', let's call them normal (60fps) and lagging (<60fps, but usually 40fps)
• The force that is applied to an object in lagging mode is double what it is in normal
• The force in lagging mode seems to be constrained to a deliberate looking number while it isn't in normal mode

Examples: Applying a force of -15000:

• Normal velocity: -10
• Lagging velocity: -19.9

Force of -30000:

• Normal: -20.6
• Lagging: -41.1

Force of -60000 (what we use on the main branch):

• Normal: -41.9
• Lagging: -60

Force of -120000:

• Normal: -84.5
• Lagging: -60