Use Fx* variants of HashMap and HashSet everywhere in Zed (#7481)

Release Notes:

- N/A

crates/theme/Cargo.toml

@@ -8,11 +8,7 @@ license = "GPL-3.0-or-later"
 [features]
 default = []
 stories = ["dep:itertools", "dep:story"]
-test-support = [
-    "gpui/test-support",
-    "fs/test-support",
-    "settings/test-support"
-]
+test-support = ["gpui/test-support", "fs/test-support", "settings/test-support"]
 
 [lib]
 path = "src/theme.rs"
@@ -20,6 +16,7 @@ doctest = false
 
 [dependencies]
 anyhow.workspace = true
+collections.workspace = true
 color.workspace = true
 derive_more.workspace = true
 fs.workspace = true