Rename mutable suites to type alias names.

[zainab-ali]

The weaver IOSuite and SimpleIOSuite are type aliases to MutableIOSuite and SimpleMutableIOSuite respectively.

These aliases were introduced as part of cats effect 3 support, when the codebase supported multiple effect types.

The codebase now only supports IO on cats effect 3, so these aliases may no longer be useful. This changeset renames the underlying Mutable* classes to these aliases.

TODO

• Add a scalafix rule renamingMutableIOSuite to IOSuite
• Remove MutableIOSuite from the docs.
• Remove the Mutable name from any internal tests.

[zainab-ali]

I'll add the scalafix rule in a follow-up PR.