build: move openbsd-arm-joelsing to Go 1.19 for bootstrap

Host is ARMv7, not ARMv5. ARMv5 toolchains segfault.
Also update cmd/buildlet's Makefile for buildlet.openbsd-arm.

For golang/go#44505.

Change-Id: I1e69bde17648466123540df1a53b730068219a1c
Reviewed-on: https://go-review.googlesource.com/c/build/+/421774
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
diff --git a/cmd/buildlet/Makefile b/cmd/buildlet/Makefile
index 16316ab..002bee6 100644
--- a/cmd/buildlet/Makefile
+++ b/cmd/buildlet/Makefile
@@ -46,7 +46,6 @@
 	buildlet.openbsd-386 \
 	buildlet.openbsd-amd64 \
 	buildlet.openbsd-arm \
-	buildlet.openbsd-arm-5 \
 	buildlet.openbsd-arm-7 \
 	buildlet.plan9-386 \
 	buildlet.plan9-amd64 \
@@ -106,7 +105,7 @@
 	cp $< $@
 buildlet.netbsd-arm: buildlet.netbsd-arm-7
 	cp $< $@
-buildlet.openbsd-arm: buildlet.openbsd-arm-5
+buildlet.openbsd-arm: buildlet.openbsd-arm-7
 	cp $< $@
 buildlet.plan9-arm: buildlet.plan9-arm-5
 	cp $< $@
diff --git a/dashboard/builders.go b/dashboard/builders.go
index f456028..ee79bff 100644
--- a/dashboard/builders.go
+++ b/dashboard/builders.go
@@ -438,7 +438,6 @@
 		IsReverse: true,
 		ExpectNum: 1,
 		Owners:    []*gophers.Person{gh("4a6f656c")},
-		HostArch:  "openbsd-arm-5",
 	},
 	"host-openbsd-arm64-joelsing": {
 		IsReverse: true,