ci: pass product name explicitly to shared build script

bread-ecosystem's ci/build.sh used to derive the image tag and cache
volume name from basename(repo_root) — but every product's CI checks
out into a directory literally named "src", so in real CI runs this
resolved to "bread-ci:src" for every product, not "bread-ci:breadpad".
Harmless while breadpad was the only consumer; would have silently
collided (shared image tag, shared cargo-target cache) the moment a
second product started using it. Fixed upstream, bumping the pin here
to pick it up and passing "breadpad" explicitly.

ci/bread-ecosystem.rev

@@ -1 +1 @@
-cd5da468b3782fddcb52b4eaff0755ff933524be
+620c5a1317a6b57276eabca961facdb78bf510db

ci/build.sh

@@ -18,4 +18,4 @@ if [ ! -d "$CACHE_DIR" ]; then
     git -C "$CACHE_DIR" checkout --quiet "$REV"
 fi
 
-bash "${CACHE_DIR}/ci/build.sh" "$ROOT" "$@"
+bash "${CACHE_DIR}/ci/build.sh" breadpad "$ROOT" "$@"