Remove submodules and unneeded files

[mcarans]

2 espeak files put in Resources
deps removed completely as no longer needed.
Remove some other unneeded files
Update README

Builds completed here: https://github.com/mcarans/oolite/actions/runs/24426014263 and you can see tests below.

Only one submodule remains: Resources/binary. I think it should be moved into the main oolite repo, but will look at this in a separate PR as can then look at completely removing submodule handling everywhere.

[mcarans]

@phkb @oocube Not sure if you saw this PR. I put you both as reviewers as it potentially touches both Windows and Linux since it removes stuff, although build and tests indicate that the PR doesn't break anything.

[oocube]

As much as I like to make building Oolite simpler - could we delay this for a moment?

Oolite builds, and even better than ever before. I love the automatic builds and this one test after that.
But: The more we change, the less we can apply old PRs that have been waiting for long.

Hence let's take decisions on the already open PRs and afterwards go for this and even more.

[mcarans]

@oocube I've looked through the current open PRs. They touch files in the src and Resources folders. This PR does not touch anything in those folders. The files removed by this PR are unused folders and contents: deps/ and Oolite.xcodeproj/ as well as a few unused files in the tools/ and installers/ folders which the open PRs do not change. Hence merging this PR will not affect those PRs.

Nevertheless, happy to delay if you prefer.

[phkb]

From a Windows build perspective, everything works fine. No issues to report.