ci: workspace mcpp bootstrap pin -> 0.0.102 (released + indexed)

0.0.102 is on all four release platforms, mirrored to xlings-res on both
GitHub and GitCode (ranged-GET verified, sha256 recomputed locally and
matched against both the upstream release and the index entry), and
xim-pkgindex PR #405 is merged with `latest` tracking it on every platform.

Also clears the E0006 the post-release fresh-install reports — the index
declares a floor of >= 0.0.101 and the pin was still 0.0.100.

Author: Sunrisepeak

.xlings.json

@@ -1,5 +1,5 @@
 {
   "workspace": {
-    "mcpp": "0.0.100"
+    "mcpp": "0.0.102"
   }
 }