Update outdated runners in the benchmarks folder (#91126)
This change updates the platform runners in the benchmarks subdir.
I've attempted to replace the entire group with new code as if the project were recreated with flutter create so that they don't become a Frankenstein of minor changes to make it work again, but just plain old generated code that can be replaced and updated in place.
diff --git a/dev/benchmarks/microbenchmarks/.metadata b/dev/benchmarks/microbenchmarks/.metadata
new file mode 100644
index 0000000..1b06421
--- /dev/null
+++ b/dev/benchmarks/microbenchmarks/.metadata
@@ -0,0 +1,10 @@
+# This file tracks properties of this Flutter project.
+# Used by Flutter tool to assess capabilities and perform upgrades etc.
+#
+# This file should be version controlled and should not be manually edited.
+
+version:
+ revision: ab51a0260d29d50800ae5c9665ecb01883a9b503
+ channel: master
+
+project_type: app
