chore: remove legacy wsconncache (#11816)

Fixes #8218

Removes `wsconncache` and related "is legacy?" functions and API calls that were used by it.

The only leftover is that Agents still use the legacy IP, so that back level clients or workspace proxies can dial them correctly.

We should eventually remove this: #11819

enterprise/coderd/workspaceproxycoordinate.go

@@ -7,42 +7,11 @@ import (
 	"nhooyr.io/websocket"
 
 	"github.com/coder/coder/v2/coderd/httpapi"
-	"github.com/coder/coder/v2/coderd/httpmw"
 	"github.com/coder/coder/v2/coderd/util/apiversion"
 	"github.com/coder/coder/v2/codersdk"
-	"github.com/coder/coder/v2/enterprise/wsproxy/wsproxysdk"
 	"github.com/coder/coder/v2/tailnet/proto"
 )
 
-// @Summary Agent is legacy
-// @ID agent-is-legacy
-// @Security CoderSessionToken
-// @Produce json
-// @Tags Enterprise
-// @Param workspaceagent path string true "Workspace Agent ID" format(uuid)
-// @Success 200 {object} wsproxysdk.AgentIsLegacyResponse
-// @Router /workspaceagents/{workspaceagent}/legacy [get]
-// @x-apidocgen {"skip": true}
-func (api *API) agentIsLegacy(rw http.ResponseWriter, r *http.Request) {
-	ctx := r.Context()
-
-	agentID, ok := httpmw.ParseUUIDParam(rw, r, "workspaceagent")
-	if !ok {
-		httpapi.Write(r.Context(), rw, http.StatusBadRequest, codersdk.Response{
-			Message: "Missing UUID in URL.",
-		})
-		return
-	}
-
-	node := (*api.AGPL.TailnetCoordinator.Load()).Node(agentID)
-	httpapi.Write(ctx, rw, http.StatusOK, wsproxysdk.AgentIsLegacyResponse{
-		Found: node != nil,
-		Legacy: node != nil &&
-			len(node.Addresses) > 0 &&
-			node.Addresses[0].Addr() == codersdk.WorkspaceAgentIP,
-	})
-}
-
 // @Summary Workspace Proxy Coordinate
 // @ID workspace-proxy-coordinate
 // @Security CoderSessionToken