Fix SourceHut jerbuild path

ober

7ed6fe360a501124c46730a632698c3cf5091f50

diff --git a/.build.yml b/.build.yml
index af4f277..456d197 100644
--- a/.build.yml
+++ b/.build.yml
@@ -20,6 +20,7 @@ packages:
   - golang-go
 environment:
   HUT_VERSION: 82e6f9fd3a5eb9c4365af43a03aecb9d5ac2ea97
+  JERBUILD: /usr/local/bin/jerbuild
   LATEST_SITE: lisp.srht.site
   LATEST_SUBDIR: /jerboa-browser/latest
   LATEST_TARBALL: jerboa-browser-linux-amd64.tar.gz