Update astro-expressive-code to v0.39 (#2777)

Co-authored-by: Chris Swithinbank <[email protected]>

.changeset/dull-mice-live.md

@@ -0,0 +1,7 @@
+---
+'@astrojs/starlight': minor
+---
+
+Updates `astro-expressive-code` dependency to the latest version (0.39).
+
+This includes an update to the latest Shiki version (1.26.1), providing access to all current Shiki themes and syntax highlighting languages. It also adds the config options `shiki.engine`, `shiki.bundledLangs`, `shiki.langAlias` and `removeUnusedThemes`. See the [Expressive Code release notes](https://expressive-code.com/releases/#0390) for full details.

packages/starlight/package.json

@@ -196,7 +196,7 @@
     "@types/hast": "^3.0.4",
     "@types/js-yaml": "^4.0.9",
     "@types/mdast": "^4.0.4",
-    "astro-expressive-code": "^0.38.3",
+    "astro-expressive-code": "^0.39.0",
     "bcp-47": "^2.1.0",
     "hast-util-from-html": "^2.0.1",
     "hast-util-select": "^6.0.2",