[Analysis API] change return type of KtScope.getAllSymbols to KtDeclaration symbol as it always returns callable or classifier

analysis/analysis-api-impl-base/src/org/jetbrains/kotlin/analysis/api/impl/base/scopes/KtCompositeScope.kt

@@ -34,7 +34,7 @@ class KtCompositeScope(
         }
     }
 
-    override fun getAllSymbols(): Sequence<KtSymbol> = withValidityAssertion {
+    override fun getAllSymbols(): Sequence<KtDeclarationSymbol> = withValidityAssertion {
         sequence {
             subScopes.forEach { yieldAll(it.getAllSymbols()) }
         }

analysis/analysis-api-impl-base/src/org/jetbrains/kotlin/analysis/api/impl/base/scopes/KtEmptyScope.kt

@@ -25,7 +25,7 @@ class KtEmptyScope(override val token: KtLifetimeToken) : KtScope {
         return emptySet()
     }
 
-    override fun getAllSymbols(): Sequence<KtSymbol> = withValidityAssertion {
+    override fun getAllSymbols(): Sequence<KtDeclarationSymbol> = withValidityAssertion {
         return emptySequence()
     }
 

analysis/analysis-api-impl-base/tests/org/jetbrains/kotlin/analysis/api/impl/base/test/cases/symbols/AbstractSymbolTest.kt

@@ -75,7 +75,7 @@ abstract class AbstractSymbolTest : AbstractAnalysisApiSingleFileTest() {
                             is KtDeclarationSymbol -> symbol.render(prettyRenderOptions)
                             is KtFileSymbol -> prettyPrint {
                                 printCollection(symbol.getFileScope().getAllSymbols().asIterable(), separator = "\n\n") {
-                                    append((it as KtDeclarationSymbol).render(prettyRenderOptions))
+                                    append(it.render(prettyRenderOptions))
                                 }
                             }