chore(cells) Reserve slugs for future potential regions (#103651)

We may need these as regions in the future.

Author: markstory

src/sentry/constants.py

@@ -122,6 +122,7 @@ def get_all_languages() -> list[str]:
         "corp",
         "customers",
         "de",
+        "de2",
         "debug",
         "devinfra",
         "docs",
@@ -213,6 +214,7 @@ def get_all_languages() -> list[str]:
         "themonitor",
         "trust",
         "us",
+        "us2",
         "vs",
         "welcome",
         "www",