MM-63200: unrestricted local admin (#30295)

* use SessionHasPermissionToCheckRestrictedAdmin

* allow unrestricted config edits from localmode

* check model.PermissionManageSystem for getLatestVersion

* simplify/clarify RequestTrialLicense semantics

* rename for clarity

* whitespace from linter

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

server/channels/api4/bleve.go

@@ -18,16 +18,11 @@ func purgeBleveIndexes(c *Context, w http.ResponseWriter, r *http.Request) {
 	auditRec := c.MakeAuditRecord("purgeBleveIndexes", audit.Fail)
 	defer c.LogAuditRec(auditRec)
 
-	if !c.App.SessionHasPermissionTo(*c.AppContext.Session(), model.PermissionPurgeBleveIndexes) {
+	if !c.App.SessionHasPermissionToAndNotRestrictedAdmin(*c.AppContext.Session(), model.PermissionPurgeBleveIndexes) {
 		c.SetPermissionError(model.PermissionPurgeBleveIndexes)
 		return
 	}
 
-	if *c.App.Config().ExperimentalSettings.RestrictSystemAdmin {
-		c.Err = model.NewAppError("purgeBleveIndexes", "api.restricted_system_admin", nil, "", http.StatusForbidden)
-		return
-	}
-
 	if err := c.App.PurgeBleveIndexes(c.AppContext); err != nil {
 		c.Err = err
 		return