cmd/mkmanifest, cmd/tailscale, cmd/tailscaled: remove Windows arm32 resources from OSS

Given recent changes in corp, I originally thought we could remove all of the
syso files, but then I realized that we still need them so that binaries built
purely from OSS (without going through corp) will still receive a manifest.

We can remove the arm32 one though, since we don't support 32-bit ARM on Windows.

Updates https://github.com/tailscale/corp/issues/9576

Signed-off-by: Aaron Klotz <aaron@tailscale.com>

cmd/mkmanifest/main.go

@@ -19,7 +19,7 @@ func main() {
 
 	arch := winres.Arch(os.Args[1])
 	switch arch {
-	case winres.ArchAMD64, winres.ArchARM64, winres.ArchI386, winres.ArchARM:
+	case winres.ArchAMD64, winres.ArchARM64, winres.ArchI386:
 	default:
 		log.Fatalf("unsupported arch: %s", arch)
 	}

cmd/tailscale/generate.go

@@ -6,4 +6,3 @@
 //go:generate go run tailscale.com/cmd/mkmanifest amd64 windows-manifest.xml manifest_windows_amd64.syso
 //go:generate go run tailscale.com/cmd/mkmanifest 386 windows-manifest.xml manifest_windows_386.syso
 //go:generate go run tailscale.com/cmd/mkmanifest arm64 windows-manifest.xml manifest_windows_arm64.syso
-//go:generate go run tailscale.com/cmd/mkmanifest arm windows-manifest.xml manifest_windows_arm.syso

cmd/tailscaled/generate.go

@@ -6,4 +6,3 @@
 //go:generate go run tailscale.com/cmd/mkmanifest amd64 windows-manifest.xml manifest_windows_amd64.syso
 //go:generate go run tailscale.com/cmd/mkmanifest 386 windows-manifest.xml manifest_windows_386.syso
 //go:generate go run tailscale.com/cmd/mkmanifest arm64 windows-manifest.xml manifest_windows_arm64.syso
-//go:generate go run tailscale.com/cmd/mkmanifest arm windows-manifest.xml manifest_windows_arm.syso