[Improvement]: Check for installed Cargo in install script

[jonaro00]

Describe the improvement

The current install scripts, install.sh and install.ps1, currently start by trying to install a cargo-shuttle binary. Only if a binary was not downloaded do they check for if cargo is installed.

The code for checking for the cargo/rust install can be moved to the beginning of the scripts.

It is fine to solve this for just one of the scripts. Up to two people can work on this one :)

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_{This issue is open to contribution. Comment if you want to work on it. Feel free to ask for help and guidance here or in our Discord.}

[Pulko]

hey 👋 would like to try working on it

[oddgrd]

Thanks @Pulko!

[jonaro00]

Solution for Linux is in progress in #1610. Contributing a solution for Powershell is still possible.

[Pulko]

@jonaro00 may I still take powershell script? Will create a PR after .sh is done so I would understand how the order should look like

[jonaro00]

Yes! Thanks for the heads up.

[Pulko]

@oddgrd hey :)

that might be an automation for closing this issue that I was not aware of unfortunately

sorry for not mentioning it here, but there is one PR left to review and merge so the issue could be completed, according to the description.

[oddgrd]

Woops, my bad, thanks @Pulko!