fix(git)!: use internal proxy for all git operations (#39426)

Introduces gitproxy module which spawns a small forward proxy as scanner
for git calls
Replaces hostmatcher with matchlist which supports port rules
Deprecates ALLOWED_DOMAINS/BLOCKED_DOMAINS and ALLOW_LOCALNETWORKS
settings in migration in favor of full names we have in security
configs.
Removes `external` preset in favor of lax/strict modes, strict mode
requiring explicit ports if they aren't standard http/s ones.

Breaking changes:
- `external` preset no longer works as deny rule. To enforce that, use
`strict` mode and allow ranges to connect to
- Wildcards are no longer accepted in IP addresses
- `*` is no longer allowed as entry in lists
- domain rules now use curl like syntax `*.example.com` matching
subdomains but not `example.com`, `example.com` matching itself and all
subdomains. `example.*` is not a valid rule
- In the default `lax` mode, `[security] ALLOWED_HOST_LIST` no longer
restricts public hosts, set `EGRESS_MODE = strict` to keep an exclusive
list. A startup warning flags this
- Invalid list entries are logged at startup, invalid
`BLOCKED_HOST_LIST`/`BLOCKED_DOMAINS` entries stop it

Docs: https://gitea.com/gitea/docs/pulls/557
Signed-off-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: bircni <bircni@icloud.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

services/migrations/github.go

@@ -17,7 +17,6 @@ import (
 	"gitea.dev/modules/git"
 	"gitea.dev/modules/log"
 	base "gitea.dev/modules/migration"
-	"gitea.dev/modules/proxy"
 	"gitea.dev/modules/structs"
 
 	"github.com/google/go-github/v92/github"
@@ -107,13 +106,8 @@ func NewGithubDownloaderV3(_ context.Context, baseURL, userName, password, token
 			}
 		}
 	} else {
-		transport := NewMigrationHTTPTransport()
-		transport.Proxy = func(req *http.Request) (*url.URL, error) {
-			req.SetBasicAuth(userName, password)
-			return proxy.Proxy()(req)
-		}
 		client := &http.Client{
-			Transport: transport,
+			Transport: &github.BasicAuthTransport{Transport: NewMigrationHTTPTransport(), Username: userName, Password: password},
 		}
 		if err := downloader.addClient(client, baseURL); err != nil {
 			return nil, err