[LL FIR] drop obsolete workaround

The original problem is already fixed

^KTIJ-26848

analysis/low-level-api-fir/src/org/jetbrains/kotlin/analysis/low/level/api/fir/util/declarationUtils.kt

@@ -190,9 +190,6 @@ var KtFile.originalKtFile by UserDataProperty(ORIGINAL_KT_FILE_KEY)
 
 
 private fun KtClassLikeDeclaration.findFir(provider: FirProvider): FirClassLikeDeclaration? {
-    // TODO, KTIJ-26848: this is a workaround for IDE index inconsistency for unnamed classes
-    if (name == null) return null
-
     return if (provider is LLFirProvider) {
         provider.getFirClassifierByDeclaration(this)
     } else {