chore(deps): record the audited 0.25.1 tree-sitter peer for the R grammar

CONTRIBUTING.md (Native tree-sitter npm packages) requires the lockfile to pin
the audited grammars' tree-sitter peer to exactly 0.25.1, as it already does for
c, cpp, java, php, ruby, rust and typescript. The R grammar entry still carried
upstream's ^0.21.0. Only the peer range changes; the upstream peerDependenciesMeta
(including its tree_sitter key typo) is untouched.

Checked: npm ci --dry-run --ignore-scripts passes in the repository root and in
gitnexus/, npm ls --depth=0 reports nothing invalid, and a fresh npm pack
(including prepack) installed into an isolated prefix passes
scripts/assert-native-parsers.mjs (20 grammars, R included) with the R
manifest's peer at 0.25.1.

gitnexus/package-lock.json

@@ -259,7 +259,7 @@
         "node-gyp-build": "^4.8.0"
       },
       "peerDependencies": {
-        "tree-sitter": "^0.21.0"
+        "tree-sitter": "0.25.1"
       },
       "peerDependenciesMeta": {
         "tree_sitter": {