ci: chmod go-w ~/.cache before pkg commands (sr.ht cache is group-writable)

ober

9ca6d73b916953b6416097fa7f973019d7d4aed1

diff --git a/.build.yml b/.build.yml
index e4afa7a..e7fa84e 100644
--- a/.build.yml
+++ b/.build.yml
@@ -30,12 +30,13 @@ tasks:
   - package-gitsafe: |
       cd jerboa-gitsafe
       J="$HOME/jerboa/dist/jerboa"
+      chmod -R go-w "$HOME/.cache"
       "$J" pkg verify
       "$J" pkg policy
       "$J" pkg build
       "$J" pkg pack --output "$PWD/jerboa-gitsafe-0.1.0.jpkg"
-      "$J" pkg verify "$PWD/jerboa-gitsafe-0.1.0.jpkg"
-      "$J" pkg verify --reproduce
+        "$J" pkg verify "$PWD/jerboa-gitsafe-0.1.0.jpkg"
+        "$J" pkg verify --reproduce
   - test-gitsafe: |
       cd jerboa-gitsafe
       JERBUILD="$HOME/jerboa/dist/jerbuild" make verify