Chore: change triggering of the detect-breaking-changes Github flow (#43188)

* chore: only run the breaking-changes flow on pull requests

* chore: run the detect-breaking-changes flow on opening a PR

* chore: use

* Wip

* Wip

* Wip

* Wip

* Wip

* Wip

* Wip

* Wip

* Wip

* Wip

* Wip

* Wip

* Wip

* Wip

* Wip

* Wip

* Wip

* trying to get workflow split running.

* trying to trigger workflow.

* trying to trigger.

* Splits levitate job into two workflows.

Co-authored-by: Marcus Andersson <marcus.andersson@grafana.com>

.github/workflows/scripts/get-workflow-run-artifact.js

@@ -0,0 +1,45 @@
+module.exports = async ({ github, context, core, runId, artifactName }) => {
+    try {
+        const AdmZip = require('adm-zip');
+        const fs = require('fs');
+
+        const { owner, repo } = context.repo;
+        const { data } = await github.rest.actions.listWorkflowRunArtifacts({
+            owner, 
+            repo, 
+            run_id: runId,
+        });
+    
+        const artifact = data.artifacts.find(a => a.name === artifactName);
+        
+        if (!artifact) {
+            throw new Error(`Could not find artifact ${artifactName} in workflow (${runId})`);
+        }
+    
+        const zip = await github.rest.actions.downloadArtifact({
+            owner,
+            repo,
+            artifact_id: artifact.id,
+            archive_format: "zip",
+        });
+    
+        const dir = `./tmp/${artifactName}`;
+        await mkdirRecursive(fs, dir);
+    
+        const admZip = new AdmZip(Buffer.from(zip.data));
+        admZip.extractAllTo(dir, true);
+
+        return dir;
+    } catch (error) {
+        core.restFailed(error.message);
+    }
+}
+
+async function mkdirRecursive(fs, path) {
+    return new Promise((resolve, reject) => {
+        fs.mkdir(path, { recursive: true }, (error) => {
+            if (error) return reject(error);
+            return resolve();
+        });
+    });
+}