chore: bump @grafana/create-plugin configuration to 5.26.4 (#2082)

Bumps
[`@grafana/create-plugin`](https://github.com/grafana/plugin-tools/tree/main/packages/create-plugin)
configuration from 4.2.1 to 5.26.4.

**Notes for reviewer:**
This is an auto-generated PR which ran `@grafana/create-plugin update`.
Please consult the create-plugin
[CHANGELOG.md](https://github.com/grafana/plugin-tools/blob/main/packages/create-plugin/CHANGELOG.md)
to understand what may have changed.
Please review the changes thoroughly before merging.

---------

Co-authored-by: grafana-plugins-platform-bot[bot] <144369747+grafana-plugins-platform-bot[bot]@users.noreply.github.com>
Co-authored-by: Zoltán Bedi <zoltan.bedi@gmail.com>

.config/webpack/BuildModeWebpackPlugin.ts

@@ -0,0 +1,33 @@
+import webpack, { type Compiler } from 'webpack';
+
+const PLUGIN_NAME = 'BuildModeWebpack';
+
+export class BuildModeWebpackPlugin {
+  apply(compiler: webpack.Compiler) {
+    compiler.hooks.compilation.tap(PLUGIN_NAME, (compilation) => {
+      compilation.hooks.processAssets.tap(
+        {
+          name: PLUGIN_NAME,
+          stage: webpack.Compilation.PROCESS_ASSETS_STAGE_ADDITIONS,
+        },
+        async () => {
+          const assets = compilation.getAssets();
+          for (const asset of assets) {
+            if (asset.name.endsWith('plugin.json')) {
+              const pluginJsonString = asset.source.source().toString();
+              const pluginJsonWithBuildMode = JSON.stringify(
+                {
+                  ...JSON.parse(pluginJsonString),
+                  buildMode: compilation.options.mode,
+                },
+                null,
+                4
+              );
+              compilation.updateAsset(asset.name, new webpack.sources.RawSource(pluginJsonWithBuildMode));
+            }
+          }
+        }
+      );
+    });
+  }
+}