Add [other].SHOW_FOOTER_POWERED_BY setting to hide Powered by (#30253)

This allows you to hide the "Powered by" text in footer via
`SHOW_FOOTER_POWERED_BY` flag in configuration.

---------

Co-authored-by: silverwind <me@silverwind.io>
(cherry picked from commit 609a627a44dbcb7b630ff51ce9f4b9f448b48ca8)

Conflicts:
	- docs/content/administration/config-cheat-sheet.en-us.md
	- docs/content/administration/config-cheat-sheet.zh-cn.md
	  Removed both, they're Gitea specific.
	- templates/base/footer_content.tmpl
	  Applied the change manually, keeping the Forgejo footer.

modules/setting/other.go

@@ -8,6 +8,7 @@ import "code.gitea.io/gitea/modules/log"
 type OtherConfig struct {
 	ShowFooterVersion          bool
 	ShowFooterTemplateLoadTime bool
+	ShowFooterPoweredBy        bool
 	EnableFeed                 bool
 	EnableSitemap              bool
 }
@@ -15,6 +16,7 @@ type OtherConfig struct {
 var Other = OtherConfig{
 	ShowFooterVersion:          true,
 	ShowFooterTemplateLoadTime: true,
+	ShowFooterPoweredBy:        true,
 	EnableSitemap:              true,
 	EnableFeed:                 true,
 }

modules/templates/helper.go

@@ -109,6 +109,9 @@ func NewFuncMap() template.FuncMap {
 		"ShowFooterTemplateLoadTime": func() bool {
 			return setting.Other.ShowFooterTemplateLoadTime
 		},
+		"ShowFooterPoweredBy": func() bool {
+			return setting.Other.ShowFooterPoweredBy
+		},
 		"AllowedReactions": func() []string {
 			return setting.UI.Reactions
 		},