Auto merge of #29461 - servo:dependabot/cargo/string_cache-0.8.6, r=jdm

Bump string_cache from 0.8.4 to 0.8.6

Bumps [string_cache](https://github.com/servo/string-cache) from 0.8.4 to 0.8.6.
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Cargo.lock

@@ -6197,9 +6197,9 @@ checksum = "9df65f20698aeed245efdde3628a6b559ea1239bbb871af1b6e3b58c413b2bd1"
 
 [[package]]
 name = "string_cache"
-version = "0.8.4"
+version = "0.8.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "213494b7a2b503146286049378ce02b482200519accc31872ee8be91fa820a08"
+checksum = "7d69e88b23f23030bf4d0e9ca7b07434f70e1c1f4d3ca7e93ce958b373654d9f"
 dependencies = [
  "new_debug_unreachable",
  "once_cell",