Update SDK to 7.0.100-alpha.1.21555.1 (#38179)

global.json

@@ -1,9 +1,9 @@
 {
   "sdk": {
-    "version": "7.0.100-alpha.1.21551.3"
+    "version": "7.0.100-alpha.1.21555.1"
   },
   "tools": {
-    "dotnet": "7.0.100-alpha.1.21551.3",
+    "dotnet": "7.0.100-alpha.1.21555.1",
     "runtimes": {
       "dotnet/x64": [
         "2.1.27",