ci: Update gvsbuild git reference

Author: sdroege

.github/workflows/windows.yml

@@ -14,7 +14,7 @@ jobs:
 
     env:
       # git revision of gvsbuild we use for to build GLib and the other dependencies
-      gvsbuildref: de70bfe8f540249aafbf8247ac6886019262917f
+      gvsbuildref: 876d21a1ecd8db1398b1dba263efee1bc3befad8
 
       # bump this number if you want to force a rebuild of gvsbuild with the same revision
       gvsbuildupdate: 1
@@ -84,7 +84,7 @@ jobs:
           - { name: "glib", test: true, args: "--features v2_80" }
           - { name: "glib-build-tools", test: false, args: "" }
           - { name: "graphene", test: false, args: "" }
-          - { name: "pango", test: true, args: "--features v1_50" }
+          - { name: "pango", test: true, args: "--features v1_52" }
           - { name: "pangocairo", test: true, args: "" }
           - { name: "examples", test: false, args: "--bins --examples --all-features" }