Add automatic JS license generation (#11810)

* Add automatic JS license generation

Removed librejs file and replaced it with a plaintext file that is built
from all JS dependencies that are included in the webpack build. It does
not cover the few remaining statically vendored files and fomantic is
added manually because it's not yet in the webpack build process.

Fixes: https://github.com/go-gitea/gitea/issues/11630

* fix lint

* remove jslicense, we're not librejs compatible any more

* remove license.txt test as it depens on absent files

* small optimization

* trailing comma

* localize and capitalize the word 'licenses'

* reduce text to just 'Licenses'

Co-authored-by: Lauris BH <lauris@nix.lv>

templates/base/footer_content.tmpl

@@ -16,7 +16,7 @@
 					{{end}}
 				</div>
 			</div>
-			<a href="{{StaticUrlPrefix}}/vendor/librejs.html" data-jslicense="1">JavaScript licenses</a>
+			<a href="{{StaticUrlPrefix}}/js/licenses.txt">{{.i18n.Tr "licenses"}}</a>
 			{{if .EnableSwagger}}<a href="{{AppSubUrl}}/api/swagger">API</a>{{end}}
 			<a target="_blank" rel="noopener noreferrer" href="https://gitea.io">{{.i18n.Tr "website"}}</a>
 			{{template "custom/extra_links_footer" .}}

templates/base/head.tmpl

@@ -52,7 +52,7 @@
 	THE SOFTWARE.
 	---
 	Licensing information for additional javascript libraries can be found at:
-	  {{StaticUrlPrefix}}/vendor/librejs.html
+	  {{StaticUrlPrefix}}/js/licenses.txt
 
 	@licend  The above is the entire license notice
         for the JavaScript code in this page.