fix(release): Manage git state after post-release (#1588)

From [Craft docs](https://github.com/getsentry/craft#post-release-script-conventions):

> The script is responsible for any and all `git` state management as `craft` will simply exit after running this script as the final step. This means the script is responsible for committing and pushing any changes that it may have made.

Git state isn't managed in the post-release script, meaning changes won't be pushed; this PR manages it.

Author: iker-barriocanal

scripts/post-release.sh

@@ -7,6 +7,7 @@ cd $SCRIPT_DIR/..
 OLD_VERSION="${1}"
 NEW_VERSION="${2}"
 
+git checkout main
 GRADLE_FILEPATH="gradle.properties"
 
 # Add a new unreleased entry in the changelog
@@ -37,3 +38,7 @@ VERSION_CODE_PATTERN="buildVersionCode"
 VERSION_NUMBER="$( awk "/$VERSION_CODE_PATTERN/" $GRADLE_FILEPATH | grep -o '[0-9]\+' )"
 ((VERSION_NUMBER++))
 sed -ie "s/$VERSION_CODE_PATTERN=.*$/$VERSION_CODE_PATTERN=$VERSION_NUMBER/g" $GRADLE_FILEPATH
+
+git add .
+git commit -m "Prepare $new_version"
+git push