chore: Add pre-release nightly demo testing issue template

Author: Techassi

.github/ISSUE_TEMPLATE/pre-release-demos-nightly.md

@@ -0,0 +1,67 @@
+---
+name: Pre-Release Demo Testing on Nightly
+about: This template can be used to track the testing of demos on nightly leading up to the next Stackable release
+title: "chore(tracking): Test demos on nightly versions"
+labels: ['epic']
+assignees: ''
+---
+
+<!--
+    Make sure to update the link in '.github/ISSUE_TEMPLATE/release.md' when
+    you change the front matter above.
+-->
+
+<!--
+    DO NOT REMOVE THIS COMMENT. It is intended for people who might copy/paste from the previous release issue.
+    This was created by an issue template: https://github.com/stackabletech/issues/issues/new/choose.
+-->
+
+## Pre-Release Demo Testing on Nightly
+
+Part of <https://github.com/stackabletech/issues/issues/TRACKING_ISSUE>
+
+For each demo, run the following commands:
+
+```shell
+# Install demo
+stackablectl demo <DEMO_NAME>
+
+# Uninstall operators
+stackablectl release uninstall <CURRENT_RELEASE>
+
+# Update CRDs to nightly version (on main)
+# Repeat this for every operator used by the demo
+kubectl replace -f https://raw.githubusercontent.com/stackabletech/commons-operator/main/deploy/helm/commons-operator/crds/crds.yaml
+
+# Install dev version of operators
+stackablectl operator install commons ...
+
+# Optionally update the product versions in the CRDs, e.g.:
+kubectl edit hbaseclusters/hbase
+```
+
+<!--
+    The following list was generated by:
+
+    # go to the demos repository, then run:
+    yq '.demos | keys' demos/demos-v2.yaml \
+    | sed -e 's/- //g' \
+    | sort \
+    | xargs -I {} echo "- [ ] [{}](https://docs.stackable.tech/home/nightly/demos/{})"
+-->
+
+```[tasklist]
+### Testing Demos on Nightly
+- [ ] [airflow-scheduled-job](https://docs.stackable.tech/home/nightly/demos/airflow-scheduled-job)
+- [ ] [data-lakehouse-iceberg-trino-spark](https://docs.stackable.tech/home/nightly/demos/data-lakehouse-iceberg-trino-spark)
+- [ ] [end-to-end-security](https://docs.stackable.tech/home/nightly/demos/end-to-end-security)
+- [ ] [hbase-hdfs-load-cycling-data](https://docs.stackable.tech/home/nightly/demos/hbase-hdfs-load-cycling-data)
+- [ ] [jupyterhub-pyspark-hdfs-anomaly-detection-taxi-data](https://docs.stackable.tech/home/nightly/demos/jupyterhub-pyspark-hdfs-anomaly-detection-taxi-data)
+- [ ] [logging](https://docs.stackable.tech/home/nightly/demos/logging)
+- [ ] [nifi-kafka-druid-earthquake-data](https://docs.stackable.tech/home/nightly/demos/nifi-kafka-druid-earthquake-data)
+- [ ] [nifi-kafka-druid-water-level-data](https://docs.stackable.tech/home/nightly/demos/nifi-kafka-druid-water-level-data)
+- [ ] [signal-processing](https://docs.stackable.tech/home/nightly/demos/signal-processing)
+- [ ] [spark-k8s-anomaly-detection-taxi-data](https://docs.stackable.tech/home/nightly/demos/spark-k8s-anomaly-detection-taxi-data)
+- [ ] [trino-iceberg](https://docs.stackable.tech/home/nightly/demos/trino-iceberg)
+- [ ] [trino-taxi-data](https://docs.stackable.tech/home/nightly/demos/trino-taxi-data)
+```