remove invalid workspaceFolder prefix from the zed rust-analyzer config

using `${workspaceFolder}` causes a lot of incorrect diagnostics on the latest version of zed

Author: cjhowe-us

src/etc/rust_analyzer_zed.json

@@ -29,15 +29,15 @@
           "compiler/rustc_codegen_gcc/Cargo.toml"
         ],
         "procMacro": {
-            "enable": true,
-            "server": "${workspaceFolder}/build/host/stage0/libexec/rust-analyzer-proc-macro-srv"
+          "enable": true,
+          "server": "build/host/stage0/libexec/rust-analyzer-proc-macro-srv"
         },
         "rustc": {
           "source": "./Cargo.toml"
         },
         "rustfmt": {
           "overrideCommand": [
-            "${workspaceFolder}/build/host/rustfmt/bin/rustfmt",
+            "build/host/rustfmt/bin/rustfmt",
             "--edition=2021"
           ]
         },