css: fix language model cache evicting at capacity instead of overflow

The `getLanguageModelCache` eviction check used `===` to compare the
current entry count against `maxEntries`, which triggered eviction as
soon as the cache reached its maximum size. As a result the cache only
held `maxEntries - 1` entries at steady state instead of the intended
`maxEntries`.

Changing the condition to `>` ensures eviction only occurs when the
count exceeds `maxEntries`, allowing the cache to retain the full
number of intended entries.

Author: claude

extensions/css-language-features/server/src/languageModelCache.ts

@@ -45,7 +45,7 @@ export function getLanguageModelCache<T>(maxEntries: number, cleanupIntervalTime
 				nModels++;
 			}
 
-			if (nModels === maxEntries) {
+			if (nModels > maxEntries) {
 				let oldestTime = Number.MAX_VALUE;
 				let oldestUri = null;
 				for (const uri in languageModels) {