UEFI: add support for tasks scheduler and make it default (#5553)

* add support for UEFI time and UEFI events; fix STOP \n -> \r\n conversion

* make it so both scheduler=none and scheduler=tasks works

* address pr comments
  - Renamed/shared the amd64 Win64 ABI task stack Go file for both Windows and UEFI.
  - Deleted the duplicate UEFI task stack Go file and old Windows-suffixed Go file.
  - Added task_stack_amd64_windows.S unconditionally to targets/uefi-amd64.json.
  - Removed the UEFI ExtraFiles() special case from compileopts/config.go.
  - Added a scheduler.none tinygo_task_exit stub.
  - Removed the custom UEFI sleep override so normal scheduler sleep queue is used.

* revert back to simpler return value for ExtraFiles()

* create uefi specific tasks_none file

* remove unused sleepSchedulerCustom stuff

* add back the uefi tag

* lib: restore macos-minimal-sdk pointer

targets/uefi-amd64.json

@@ -6,7 +6,7 @@
   "goos": "linux",
   "goarch": "amd64",
   "gc": "leaking",
-  "scheduler": "none",
+  "scheduler": "tasks",
   "linker": "ld.lld",
   "linker-flavor": "coff",
   "libc": "picolibc",
@@ -35,7 +35,8 @@
   "extra-files": [
     "src/device/amd64/cpu_amd64.S",
     "src/device/uefi/asm_amd64.S",
-    "src/runtime/asm_amd64_windows.S"
+    "src/runtime/asm_amd64_windows.S",
+    "src/internal/task/task_stack_amd64_windows.S"
   ],
   "gdb": ["gdb-multiarch", "gdb"]
 }