mcrouter: disable Windows builds via getdeps manifest

Summary:
mcrouter is not supported on Windows — its dependencies (folly, fizz, wangle, fbthrift, mvfst) build there but mcrouter itself doesn't. Teach the getdeps manifest to skip the Windows build by selecting the `nop` builder when `os=windows`, matching the pattern used by `proxygen`, `moxygen`, and other manifests that are linux/macOS-only.

Without this, getdeps attempts to run cmake on Windows and fails partway through. With this change, mcrouter is treated as a no-op on Windows so dependency walks and CI runs succeed cleanly.

Reviewed By: alikhtarov

Differential Revision: D105243284

fbshipit-source-id: 0c9b1c4b0e1a370adc50490ded3176786b09dbcb

Author: David Huynh (Infra)

build/fbcode_builder/manifests/mcrouter

@@ -32,6 +32,9 @@ fbcode/mcrouter = mcrouter
 [build]
 builder = cmake
 
+[build.os=windows]
+builder = nop
+
 [cmake.defines]
 BUILD_SHARED_LIBS=OFF