Fix dependency conflict warnings (#8376)

Update the git url of `swift-llbuild` and `swift-tools-support-core` so
they point to the swiftlang github orginization.

Author: bkhouri

Package.swift

@@ -1001,7 +1001,7 @@ let relatedDependenciesBranch = "main"
 if ProcessInfo.processInfo.environment["SWIFTPM_LLBUILD_FWK"] == nil {
     if ProcessInfo.processInfo.environment["SWIFTCI_USE_LOCAL_DEPS"] == nil {
         package.dependencies += [
-            .package(url: "https://github.com/apple/swift-llbuild.git", branch: relatedDependenciesBranch),
+            .package(url: "https://github.com/swiftlang/swift-llbuild.git", branch: relatedDependenciesBranch),
         ]
     } else {
         // In Swift CI, use a local path to llbuild to interoperate with tools
@@ -1017,7 +1017,7 @@ if ProcessInfo.processInfo.environment["SWIFTPM_LLBUILD_FWK"] == nil {
 
 if ProcessInfo.processInfo.environment["SWIFTCI_USE_LOCAL_DEPS"] == nil {
     package.dependencies += [
-        .package(url: "https://github.com/apple/swift-tools-support-core.git", branch: relatedDependenciesBranch),
+        .package(url: "https://github.com/swiftlang/swift-tools-support-core.git", branch: relatedDependenciesBranch),
         // The 'swift-argument-parser' version declared here must match that
         // used by 'swift-driver' and 'sourcekit-lsp'. Please coordinate
         // dependency version changes here with those projects.