feat: abra release now asks for a release note (!393)

This implements coop-cloud/organising#540 by checking if a`release/next` file exists and if so moves it to `release/<tag>`. When no release notes exists it prompts for them.

Reviewed-on: coop-cloud/abra#393
Reviewed-by: moritz <moritz.m@local-it.org>
Co-authored-by: p4u1 <p4u1_f4u1@riseup.net>
Co-committed-by: p4u1 <p4u1_f4u1@riseup.net>

tests/integration/helpers/git.bash

@@ -28,3 +28,10 @@ _reset_tags() {
   assert_success
   refute_output '0'
 }
+
+_set_git_author() {
+  run git -C "$ABRA_DIR/recipes/$TEST_RECIPE" config --local user.email test@example.com
+  assert_success
+  run git -C "$ABRA_DIR/recipes/$TEST_RECIPE" config --local user.name test
+  assert_success
+}