[docs] removed static URL to LogQL Analyzer API (#7773)

added logic to determine logql-analyzer version dynamically based on the
value selected in docs version dropdown.
Adding this logic to the docs, allows us to skip the step on release
when we manually update the link to the new version of LogQL Analyzer

docs/sources/logql/analyzer/script.js

@@ -1,4 +1,3 @@
-let host = "https://logql-analyzer.grafana.net/next";
 Handlebars.registerHelper("inc", (val) => parseInt(val) + 1);
 let streamSelector = `{job="analyze"}`;
 const logsSourceInputElement = document.getElementById("logs-source-input");
@@ -89,7 +88,27 @@ function handleError(error) {
   resultsElement.classList.add("hide");
 }
 
+// Loki version in docs always looks like `MAJOR.MINOR.x`
+const lokiVersionRegexp = /(\d+\.\d+\.x)/
+const baseAnalyzerHost = "https://logql-analyzer.grafana.net";
+
+function getSelectedDocsVersionTitle() {
+  let selectedDocsVersion = document.querySelector("#grafana-version-select > option:checked");
+  // we need to return "next" for the local development. in this case we do not have version selector
+  return selectedDocsVersion && selectedDocsVersion.text || "next";
+}
+
+function getAnalyzerHost() {
+  const docsVersionTitle = getSelectedDocsVersionTitle();
+  const matches = docsVersionTitle.match(lokiVersionRegexp);
+  if (matches === null || matches.length === 0) {
+    return `${baseAnalyzerHost}/next`
+  }
+  return `${baseAnalyzerHost}/${matches[0].replaceAll(".", "-")}`
+}
+
 async function sendRequest(payload) {
+  const host = getAnalyzerHost();
   return fetch(host + "/api/logql-analyze", {
     method: 'POST', headers: {
       'Accept': 'application/json', 'Content-Type': 'application/json'