ci: set umask 022 in package/verify tasks too (jerbuild creates group-writable cache dirs during pkg operations)

ober

9d05574aa18c3a6996a4f0db9341794ce28ccc58

diff --git a/.build.yml b/.build.yml
index cd65c16..dc59ee8 100644
--- a/.build.yml
+++ b/.build.yml
@@ -43,6 +43,7 @@ tasks:
       make jerboa CHEZ_CONFIGURE_EXTRA=--disable-x11 JERBOA_NATIVE_FEATURES=tls JERBOA_CC_OPT=-O0
       echo 'export PATH="$HOME/jerboa/dist:$PATH"' >> ~/.buildenv
   - package-code: |
+      umask 022
       cd jerboa-code
       J="$HOME/jerboa/dist/jerboa"
       mkdir -p "$HOME/.cache" && chmod -R go-w "$HOME/.cache"