See if we can fix sr.ht build due to change in install.

.builds/freebsd.yml

@@ -9,3 +9,4 @@ tasks:
     gmake
     gmake test
     sudo gmake install
+    sudo gmake uninstall

.builds/openbsd.yml

@@ -11,6 +11,7 @@ tasks:
     gmake test
     doas gmake install
     gmake test-install
+    doas gmake uninstall
 - meson_min: |
     cd janet
     meson setup build_meson_min --buildtype=release -Dsingle_threaded=true -Dnanbox=false -Ddynamic_modules=false -Ddocstrings=false -Dnet=false -Dsourcemaps=false -Dpeg=false -Dassembler=false -Dint_types=false -Dreduced_os=true -Dffi=false