Loosen astropy version restriction (#51)

* loosen astropy version restriction to ">=5.3"

* fixup docs

* prep release v0.3.8. update CHANGELOG.

CHANGELOG.md

@@ -12,6 +12,13 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 
 (none)
 
+## \[v0.3.8\] - 2024-07-02
+
+### Changed
+
+- Loosen `astropy` version restriction to ">=5.3". `astropy` v<6.0.0 is required by `supernnova` v3.0.1
+  which is not a direct dependency of `pittgoogle-client` but is often used with it.
+
 ## \[v0.3.7\] - 2024-07-02
 
 ### Added

docs/source/for-developers/release-new-version.md

@@ -21,13 +21,16 @@ By following these instructions, you will:
     - Under "Write", paste in the relevant section of CHANGELOG.md describing the release.
     - Click "Publish release".
 
-Completing step 3 will:
+Completing step 3 will (or should):
 
 - Tag a new version on GitHub.
 - Publish the documentation to GitHub pages.
 - Publish the package to PyPI.org.
 
-You will now be able to install the new version using:
+View the [GitHub Actions](https://github.com/mwvgroup/pittgoogle-client/actions) page to see the
+status of the release process.
+
+If all went well, you will now be able to install the new version using:
 
 ```bash
 pip install --upgrade pittgoogle-client

pyproject.toml

@@ -30,7 +30,7 @@ classifiers = [
 # https://python-poetry.org/docs/dependency-specification/#git-dependencies
 python = "^3.9"
 attrs = ">=23.1"
-astropy = ">=6.0"
+astropy = ">=5.3"  # v<6.0.0 required by supernnova 3.0.1
 fastavro = ">=1.7.4"
 google-auth-oauthlib = ">=1.0"
 google-cloud-bigquery = ">=3.11.2"