docs(ci): add notes about libpq caching

diff --git a/.github/workflows/packages-bin.yml b/.github/workflows/packages-bin.yml
index fb43ac877c093252e6d9097064017fc5e9cd5024..f84e627743f440a71f07c08cb1e5d32d30c8fd10 100644 (file)
--- a/.github/workflows/packages-bin.yml
+++ b/.github/workflows/packages-bin.yml
@@ -1,5 +1,20 @@
 name: Build binary packages
 
+# Note: Libpq is currently built from source on most platform and the build
+# cached across pipeline runs.
+#
+# You can see the caches at https://github.com/psycopg/psycopg/actions/caches
+#
+# You can delete a cache using:
+#
+#   curl -L -X DELETE
+#     -H "Accept: application/vnd.github+json"
+#     -H "Authorization: Bearer $GITHUB_TOKEN"
+#     -H "X-GitHub-Api-Version: 2022-11-28"
+#     "https://api.github.com/repos/psycopg/psycopg/actions/caches?key=libpq-manylinux-ppc64le-17.2-3.4.0"
+#
+# ref: https://docs.github.com/en/rest/actions/cache?apiVersion=2022-11-28#delete-github-actions-caches-for-a-repository-using-a-cache-key
+
 on:
   workflow_dispatch:
   schedule: