refactor!: move go-chi/session into Gitea (#39504)

The `gitea.com/go-chi/session` package only exists for Gitea, so it
moves into `modules/session` to fix its bugs directly. Fixes the flake
in
https://github.com/go-gitea/gitea/actions/runs/36726154500/job/109923538400.

- Sessions are only written back when changed, so a read-only request
can't revert a concurrent change or restore a logged-out session, like
https://github.com/go-macaron/session/commit/ae808a4a4660c802965c834299ab08f167effd12
- The session cookie is only set once a session holds data
- Every backend refreshes the expiry on load and file sessions are
written atomically
- Also fix  https://github.com/go-gitea/gitea/issues/36176

## ⚠️ BREAKING ⚠️

* the `mysql`, `postgres`, `couchbase` and `memcache` session providers
are removed, use `file`, `db` or `redis` instead
* login-related cookies are renamed to `gitea_session` and
`gitea_remember`, if you'd like to use the old names, set `COOKIE_NAME`
and `COOKIE_REMEMBER_NAME` in app.ini

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

cmd/dump.go

@@ -13,13 +13,11 @@ import (
 
 	"gitea.dev/models/db"
 	"gitea.dev/modules/dump"
-	"gitea.dev/modules/json"
 	"gitea.dev/modules/log"
 	"gitea.dev/modules/setting"
 	"gitea.dev/modules/storage"
 	"gitea.dev/modules/util"
 
-	"gitea.com/go-chi/session"
 	"github.com/urfave/cli/v3"
 )
 
@@ -249,12 +247,8 @@ func runDump(ctx context.Context, cmd *cli.Command) error {
 		log.Info("Packing data directory...%s", setting.AppDataPath)
 
 		var excludes []string
-		if setting.SessionConfig.OriginalProvider == "file" {
-			var opts session.Options
-			if err = json.Unmarshal([]byte(setting.SessionConfig.ProviderConfig), &opts); err != nil {
-				return err
-			}
-			excludes = append(excludes, opts.ProviderConfig)
+		if setting.SessionConfig.Provider == "file" {
+			excludes = append(excludes, setting.SessionConfig.ProviderConfig)
 		}
 
 		if cmd.IsSet("skip-index") && cmd.Bool("skip-index") {