Update Swift Dockerfile to use Swift 6.0.1

[tonyarnold]

What are you trying to accomplish?

The Swift Project has recently released Swift 6.0, and I would like Dependabot to continue working with my projects once I have updated them to this language version.

How will you know you've accomplished your goal?

Dependabot will be able to interact with Swift packages using the Swift 6.0 tools.

[jurre]

Thanks @tonyarnold! Do you happen to know if this version is backwards compatible? The tests are passing so I'd assume so, but I've been out of the Swift game for a bit now so figured I'd check with you.

[tonyarnold]

To a point, yes. How do other language support modules handle major version updates?

[jurre]

It depends a little bit on the ecosystem/language tbh, in some cases we have some workarounds to make versions backwards compatible, in exceptional cases we have first class support for multiple versions. In most cases things are backwards compatible enough to work in most cases and/or upgrading is easy enough for customers

[tonyarnold]

My understanding is that Swift 6.0 can interact with Swift Packages that specify older tools versions via // swift-tools-version:5.10 and similar, so this should be safe to move forward with.