ci: run crates.io publish on release tags

rust-bindings/rust/.gitlab-ci.yml

@@ -92,11 +92,13 @@ publish_ostree-sys:
   script:
   - cargo publish --verbose --manifest-path sys/Cargo.toml --token $CRATES_IO_TOKEN
   cache: {}
-  when: manual
+  only:
+  - /^ostree-sys\/.+$/
 
 publish_ostree:
   stage: publish
   script:
   - cargo publish --verbose --token $CRATES_IO_TOKEN
   cache: {}
-  when: manual
+  only:
+  - /^ostree\/.+$/

rust-bindings/rust/README.md

@@ -92,9 +92,9 @@ The version needs to be changed in the following places (if applicable):
 * in `Cargo.toml` for the main crate version
 * in `README.md` in the *Installing* section in case of major version bumps
 
-Then, run the publish jobs on the release commit. Main and -sys crate don't have
+ Then tag the commit as `ostree/x.y.z` and/or `ostree-sys/x.y.z`. This will run
-to be released in lockstep. Then tag the commit as `ostree/x.y.z` and/or
+ the crates.io deployment jobs. Main and -sys crate don't have to be released in
-`ostree-sys/x.y.z`.
+ lockstep.
 
 ## License
 The `ostree` crate is licensed under the MIT license. See the LICENSE file for