ui2: Remove dependency on theme crate

Cargo.lock

@@ -9488,7 +9488,6 @@ dependencies = [
  "serde",
  "smallvec",
  "strum",
- "theme",
  "theme2",
 ]
 

crates/ui2/Cargo.toml

@@ -12,7 +12,6 @@ itertools = { version = "0.11.0", optional = true }
 serde.workspace = true
 smallvec.workspace = true
 strum = { version = "0.25.0", features = ["derive"] }
-theme = { path = "../theme" }
 theme2 = { path = "../theme2" }
 rand = "0.8"