lib/licenses: add bsdAxisNoDisclaimerUnmodified

This is a variant composed of clause 1 and 3 of a BSD-Modified found in the
Linux kernel and this extra variant has the words "without modification" added
at the end of clause 1 either with or without a comma. It also lacks the
warranty disclaimer.

See <https://scancode-licensedb.aboutcode.org/bsd-no-disclaimer-unmodified.html>.

lib/licenses.nix

@@ -220,6 +220,11 @@ lib.mapAttrs mkLicense ({
     fullName = "Lawrence Berkeley National Labs BSD variant license";
   };
 
+  bsdAxisNoDisclaimerUnmodified = {
+    fullName = "BSD-Axis without Warranty Disclaimer with Unmodified requirement";
+    url = "https://scancode-licensedb.aboutcode.org/bsd-no-disclaimer-unmodified.html";
+  };
+
   bsdOriginal = {
     spdxId = "BSD-4-Clause";
     fullName = ''BSD 4-clause "Original" or "Old" License'';