Auto merge of #20819 - servo:fourchette, r=jdm

Remove unused build targets

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components/style/Cargo.toml

@@ -16,13 +16,13 @@ path = "lib.rs"
 doctest = false
 
 [features]
-gecko = ["nsstring", "num_cpus",
+gecko = ["num_cpus",
          "style_traits/gecko", "fallible/known_system_malloc"]
 use_bindgen = ["bindgen", "regex", "toml"]
 servo = ["serde", "style_traits/servo", "servo_atoms", "servo_config", "html5ever",
          "cssparser/serde", "encoding_rs", "malloc_size_of/servo", "arrayvec/use_union",
          "servo_url", "string_cache"]
-gecko_debug = ["nsstring/gecko_debug"]
+gecko_debug = []
 
 [dependencies]
 app_units = "0.6"
@@ -46,7 +46,6 @@ log = "0.4"
 malloc_size_of = { path = "../malloc_size_of" }
 malloc_size_of_derive = { path = "../malloc_size_of_derive" }
 matches = "0.1"
-nsstring = {path = "../../support/gecko/nsstring", optional = true}
 num_cpus = {version = "1.1.0", optional = true}
 num-integer = "0.1.32"
 num-traits = "0.1.32"