chore: Only release-plz after release PRs (#524)

Stops releases from being created by new packages pushed to `main`.

https://release-plz.ieni.dev/docs/config#the-release_always-field

This saves us from having to temporarily configure `git_tag_enable` and
`git_release_enable` for each crate.
73d6e65

release-plz.toml

@@ -12,6 +12,13 @@ release = false
 git_tag_name = "{{ package }}-v{{ version }}"
 git_release_name = "{{ package }}: v{{ version }}"
 
+# Only create releases / push to crates.io after merging a release-please PR.
+# This lets merge new crates to `main` without worrying about accidentally creating
+# github releases.
+#
+# To trigger a release manually, merge a PR from a branch starting with `release-plz-`.
+release_always = false
+
 [changelog]
 sort_commits = "oldest"