remove "regex" from options/ai/ai.proto (#10641)

Author: sheidkamp

changelog/v1.18.9/ai-options-proto-fix.yaml

@@ -0,0 +1,6 @@
+changelog:
+  - type: FIX
+    issueLink: https://github.com/solo-io/solo-projects/issues/7875
+    resolvesIssue: false
+    description: >-
+      Remove `regex` field from ai options proto enum to avoid generated code conflicts with `REGEX` field

docs/content/reference/api/github.com/solo-io/gloo/projects/gloo/api/v1/enterprise/options/ai/ai.proto.sk.md

@@ -646,7 +646,6 @@ message AIPromptGuard {
     message HeaderMatch {
       // The header string match type.
       enum MatchType {
-        option allow_alias = true;
         // The string must match exactly the specified string.
         EXACT = 0;
         // The string must have the specified prefix.
@@ -657,8 +656,6 @@ message AIPromptGuard {
         CONTAINS = 3;
         // The string must match the specified [RE2-style regular expression](https://github.com/google/re2/wiki/) pattern.
         REGEX = 4;
-        // Do not use. Use `REGEX` (fully capitalized) instead.
-        regex = 4;
       }
       // The header key string to match against.
       string key = 1;