cody-gateway/actor: version actor source caches (#53263)

We've run into issues a few times now where the cache doesn't update
fast enough on a breaking change. This adds a version prefix that allows
us to invalidate caches on certain rollouts.

Depends on https://github.com/sourcegraph/sourcegraph/pull/53265 being
rolled out to all environments.

## Test plan

Run locally with new prefix

Author: bobheadxi

enterprise/cmd/cody-gateway/internal/actor/dotcomuser/dotcomuser.go

@@ -18,6 +18,10 @@ import (
 	"github.com/sourcegraph/sourcegraph/lib/errors"
 )
 
+// SourceVersion should be bumped whenever the format of any cached data in this
+// actor source implementation is changed. This effectively expires all entries.
+const SourceVersion = "v1"
+
 // dotcom user gateway tokens are always a prefix of 4 characters (sgd_)
 // followed by a 64-character hex-encoded SHA256 hash
 const tokenLength = 4 + 64

enterprise/cmd/cody-gateway/internal/actor/productsubscription/productsubscription.go

@@ -23,6 +23,10 @@ import (
 	"github.com/sourcegraph/sourcegraph/lib/errors"
 )
 
+// SourceVersion should be bumped whenever the format of any cached data in this
+// actor source implementation is changed. This effectively expires all entries.
+const SourceVersion = "v1"
+
 // product subscription tokens are always a prefix of 4 characters (sgs_ or slk_)
 // followed by a 64-character hex-encoded SHA256 hash
 const tokenLength = 4 + 64

enterprise/cmd/cody-gateway/shared/main.go

@@ -2,6 +2,7 @@ package shared
 
 import (
 	"context"
+	"fmt"
 	"net/http"
 	"net/url"
 	"os"
@@ -77,13 +78,13 @@ func Main(ctx context.Context, obctx *observation.Context, ready service.ReadyFu
 		anonymous.NewSource(config.AllowAnonymous, config.ActorConcurrencyLimit),
 		productsubscription.NewSource(
 			obctx.Logger,
-			rcache.NewWithTTL("product-subscriptions", int(config.SourcesCacheTTL.Seconds())),
+			rcache.NewWithTTL(fmt.Sprintf("product-subscriptions:%s", productsubscription.SourceVersion), int(config.SourcesCacheTTL.Seconds())),
 			dotcomClient,
 			config.Dotcom.InternalMode,
 			config.ActorConcurrencyLimit,
 		),
 		dotcomuser.NewSource(obctx.Logger,
-			rcache.NewWithTTL("dotcom-users", int(config.SourcesCacheTTL.Seconds())),
+			rcache.NewWithTTL(fmt.Sprintf("dotcom-users:%s", dotcomuser.SourceVersion), int(config.SourcesCacheTTL.Seconds())),
 			dotcomClient,
 			config.ActorConcurrencyLimit,
 		),