Bump the macOS deployment target to 10.13 in the Xcode project.

Xcode 15 no longer recognizes 10.12 as a valid deployment target and just
falls back to 14.2, which is too new for our CI.

Author: kateinoigakukun

Foundation.xcodeproj/project.pbxproj

@@ -3868,7 +3868,7 @@
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
 				LD_RUNPATH_SEARCH_PATHS = "$(TOOLCHAIN_DIR)/usr/lib/swift/macosx";
-				MACOSX_DEPLOYMENT_TARGET = 10.12;
+				MACOSX_DEPLOYMENT_TARGET = 10.13;
 				MTL_ENABLE_DEBUG_INFO = YES;
 				ONLY_ACTIVE_ARCH = YES;
 				SDKROOT = macosx;
@@ -3924,7 +3924,7 @@
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
 				LD_RUNPATH_SEARCH_PATHS = "$(TOOLCHAIN_DIR)/usr/lib/swift/macosx";
-				MACOSX_DEPLOYMENT_TARGET = 10.12;
+				MACOSX_DEPLOYMENT_TARGET = 10.13;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				SDKROOT = macosx;
 				SWIFT_COMPILATION_MODE = wholemodule;
@@ -4268,7 +4268,7 @@
 					"@loader_path/../../..",
 					"@executable_path/../Frameworks",
 				);
-				MACOSX_DEPLOYMENT_TARGET = 10.12;
+				MACOSX_DEPLOYMENT_TARGET = 10.13;
 				PRODUCT_BUNDLE_IDENTIFIER = org.swift.xdgTestHelper;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_ACTIVE_COMPILATION_CONDITIONS = DEBUG;
@@ -4299,7 +4299,7 @@
 					"@loader_path/../../..",
 					"@executable_path/../Frameworks",
 				);
-				MACOSX_DEPLOYMENT_TARGET = 10.12;
+				MACOSX_DEPLOYMENT_TARGET = 10.13;
 				PRODUCT_BUNDLE_IDENTIFIER = org.swift.xdgTestHelper;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_VERSION = 5.0;