Enable more revive linter rules (#30608)

Noteable additions:

- `redefines-builtin-id` forbid variable names that shadow go builtins
- `empty-lines` remove unnecessary empty lines that `gofumpt` does not
remove for some reason
- `superfluous-else` eliminate more superfluous `else` branches

Rules are also sorted alphabetically and I cleaned up various parts of
`.golangci.yml`.

routers/api/packages/goproxy/goproxy.go

@@ -154,12 +154,12 @@ func resolvePackage(ctx *context.Context, ownerID int64, name, version string) (
 }
 
 func UploadPackage(ctx *context.Context) {
-	upload, close, err := ctx.UploadStream()
+	upload, needToClose, err := ctx.UploadStream()
 	if err != nil {
 		apiError(ctx, http.StatusInternalServerError, err)
 		return
 	}
-	if close {
+	if needToClose {
 		defer upload.Close()
 	}