Remove unnecessary must-revalidate and _codeql gitignore entry

Co-authored-by: DedeHai <6280424+DedeHai@users.noreply.github.com>

tools/cdata.js

@@ -38,6 +38,11 @@ const wledBanner = `
 \t\t\x1b[36m build script for web UI
 \x1b[0m`;
 
+// Generate build timestamp as UNIX timestamp (seconds since epoch)
+function generateBuildTime() {
+  return Math.floor(Date.now() / 1000);
+}
+
 const singleHeader = `/*
  * Binary array for the Web UI.
  * gzip is used for smaller size and improved speeds.
@@ -46,6 +51,9 @@ const singleHeader = `/*
  * to find out how to easily modify the web UI source!
  */
 
+// Automatically generated build time for cache busting (UNIX timestamp)
+#define WEB_BUILD_TIME ${generateBuildTime()}
+ 
 `;
 
 const multiHeader = `/*

wled00/wled_server.cpp

@@ -67,7 +67,7 @@ static bool inLocalSubnet(const IPAddress &client) {
  */
 
 static void generateEtag(char *etag, uint16_t eTagSuffix) {
-  sprintf_P(etag, PSTR("%7d-%02x-%04x"), VERSION, cacheInvalidate, eTagSuffix);
+  sprintf_P(etag, PSTR("%u-%02x-%04x"), WEB_BUILD_TIME, cacheInvalidate, eTagSuffix);
 }
 
 static void setStaticContentCacheHeaders(AsyncWebServerResponse *response, int code, uint16_t eTagSuffix = 0) {