Auto merge of #18446 - bzbarsky:update-cssparser, r=SimonSapin

Update rust-cssparser to 0.20.2.

This reduces memory consumption of list-valued properties in the common case of one entry in the list.

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components/style/Cargo.toml

@@ -36,7 +36,7 @@ atomic_refcell = "0.1"
 bitflags = "0.7"
 byteorder = "1.0"
 cfg-if = "0.1.0"
-cssparser = "0.20"
+cssparser = "0.20.2"
 encoding = {version = "0.2", optional = true}
 euclid = "0.15"
 fallible = { path = "../fallible" }