newlib-nano: Printf formatting does not work properly with "PRIu8"

[fjmolinas]

Description

When using "PRIu8" and if using newlib then it gets formatted as hu. This does not happen with picolibc.

Related to #1891, but as that one focuses on floats, a new issue is oppened.

Steps to reproduce the issue

Try a PRIu8 formated printf, eg with this diff:

diff --git a/examples/hello-world/main.c b/examples/hello-world/main.c
index f51bf8c0a0..d5fc3cf12d 100644
--- a/examples/hello-world/main.c
+++ b/examples/hello-world/main.c
@@ -20,6 +20,7 @@
  */
 
 #include <stdio.h>
+#include "inttypes.h"
 
 int main(void)
 {
@@ -28,5 +29,8 @@ int main(void)
     printf("You are running RIOT on a(n) %s board.\n", RIOT_BOARD);
     printf("This board features a(n) %s MCU.\n", RIOT_MCU);
 
+    uint8_t num = 24;
+    printf("'%"PRIu8"' should be '24'\n", num);
+
     return 0;
 }

Expected results

'24' should be '24'

Actual results

'hu' should be '24'

Versions

BUILD_IN_DOCKER=1

[maribu]

duplicate of #1891