Automate collapsing ARN table in release notes (#2071)

* Automate collapsing ARN table in release notes

* Apply suggestions from code review

---------

Co-authored-by: Riccardo Magliocchetti <riccardo.magliocchetti@gmail.com>

Author: reakaleek

.ci/create-arn-table.sh

@@ -10,7 +10,8 @@ AWS_FOLDER=${AWS_FOLDER?:No aws folder provided}
 ARN_FILE=".arn-file.md"
 
 {
-	echo "### Elastic APM Python agent layer ARNs"
+	echo "<details>"
+	echo "<summary>Elastic APM Python agent layer ARNs</summary>"
 	echo ''
 	echo '|Region|ARN|'
 	echo '|------|---|'
@@ -22,4 +23,8 @@ for f in $(ls "${AWS_FOLDER}"); do
 	echo "|${f}|${LAYER_VERSION_ARN}|" >> "${ARN_FILE}"
 done
 
-echo '' >> "${ARN_FILE}"
+{
+	echo ''
+	echo '</details>'
+	echo ''
+} >> "${ARN_FILE}"

CONTRIBUTING.md

@@ -198,4 +198,4 @@ If you have commit access, the process is as follows:
 1. After tests pass, Github Actions will automatically build and push the new release to PyPI.
 1. Edit and publish the [draft Github release](https://github.com/elastic/apm-agent-python/releases)
    created by Github Actions. Substitute the generated changelog with one hand written into the body of the
-   release and move the agent layer ARNs under a `<details>` block with a `summary`.
+   release.