[PlaygroundSupport] Removed a couple of vestigial shell script build phases for copying swiftdoc files.

These were added before Xcode's build system supported copying swiftdoc files on its own.
They've been harmless for the last several years, but because they hard-coded `x86_64`, it means they don't work when building PlaygroundSupport.framework (or the legacy XCPlayground.framework) for `arm64` only.
As a result, this commit removes these vestigial build phases; Xcode's built-in support for swiftdoc files is better than these ever were.

This addresses <rdar://problem/75513867>.

Author: cwakamo

PlaygroundSupport/PlaygroundSupport.xcodeproj/project.pbxproj

@@ -592,7 +592,6 @@
 				1DF4117018DCB596001CDFC7 /* Frameworks */,
 				1DF4117218DCB596001CDFC7 /* Headers */,
 				1DF4117318DCB596001CDFC7 /* Resources */,
-				5EB831EE19247927007D5493 /* Copy swiftdoc */,
 			);
 			buildRules = (
 			);
@@ -631,7 +630,6 @@
 				A8318F921CF603630015809A /* Sources */,
 				A8318F981CF603630015809A /* Frameworks */,
 				A8318F9A1CF603630015809A /* Resources */,
-				A8318F9C1CF603630015809A /* Copy swiftdoc */,
 			);
 			buildRules = (
 			);
@@ -878,6 +876,7 @@
 			developmentRegion = English;
 			hasScannedForEncodings = 0;
 			knownRegions = (
+				English,
 				en,
 			);
 			mainGroup = 1D7FD51118BFE00400C718C6;
@@ -1009,34 +1008,6 @@
 			shellPath = /bin/sh;
 			shellScript = "swiftc -v";
 		};
-		5EB831EE19247927007D5493 /* Copy swiftdoc */ = {
-			isa = PBXShellScriptBuildPhase;
-			buildActionMask = 2147483647;
-			files = (
-			);
-			inputPaths = (
-			);
-			name = "Copy swiftdoc";
-			outputPaths = (
-			);
-			runOnlyForDeploymentPostprocessing = 0;
-			shellPath = /bin/bash;
-			shellScript = "# Copy x86_64's swiftdoc from the object file dir to the target build dir.\nsrc_swiftdoc=\"${OBJECT_FILE_DIR_normal}/x86_64/${PRODUCT_MODULE_NAME}.swiftdoc\"\ndst_swiftdoc=\"${TARGET_BUILD_DIR}/${CONTENTS_FOLDER_PATH}/Modules/${PRODUCT_MODULE_NAME}.swiftmodule/x86_64.swiftdoc\"\n\necho \"Copying swiftdoc for XCPlayground.framework\"\ncp -v \"${src_swiftdoc}\" \"${dst_swiftdoc}\"";
-		};
-		A8318F9C1CF603630015809A /* Copy swiftdoc */ = {
-			isa = PBXShellScriptBuildPhase;
-			buildActionMask = 2147483647;
-			files = (
-			);
-			inputPaths = (
-			);
-			name = "Copy swiftdoc";
-			outputPaths = (
-			);
-			runOnlyForDeploymentPostprocessing = 0;
-			shellPath = /bin/bash;
-			shellScript = "# Copy x86_64's swiftdoc from the object file dir to the target build dir.\nsrc_swiftdoc=\"${OBJECT_FILE_DIR_normal}/x86_64/${PRODUCT_MODULE_NAME}.swiftdoc\"\ndst_swiftdoc=\"${TARGET_BUILD_DIR}/${CONTENTS_FOLDER_PATH}/Modules/${PRODUCT_MODULE_NAME}.swiftmodule/x86_64.swiftdoc\"\n\necho \"Copying swiftdoc for XCPlayground.framework\"\ncp -v \"${src_swiftdoc}\" \"${dst_swiftdoc}\"";
-		};
 /* End PBXShellScriptBuildPhase section */
 
 /* Begin PBXSourcesBuildPhase section */