caps: add cap for gha cache backend

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

cache/remotecache/gha/gha.go

@@ -331,7 +331,7 @@ func (r *readerAt) Size() int64 {
 }
 
 func oneOffProgress(ctx context.Context, id string) func(err error) error {
-	pw, _, _ := progress.FromContext(ctx)
+	pw, _, _ := progress.NewFromContext(ctx)
 	now := time.Now()
 	st := progress.Status{
 		Started: &now,

solver/pb/caps.go

@@ -62,6 +62,8 @@ const (
 	CapMetaIgnoreCache apicaps.CapID = "meta.ignorecache"
 	CapMetaDescription apicaps.CapID = "meta.description"
 	CapMetaExportCache apicaps.CapID = "meta.exportcache"
+
+	CapRemoteCacheGHA apicaps.CapID = "cache.gha"
 )
 
 func init() {
@@ -339,4 +341,10 @@ func init() {
 		Enabled: true,
 		Status:  apicaps.CapStatusExperimental,
 	})
+
+	Caps.Init(apicaps.Cap{
+		ID:      CapRemoteCacheGHA,
+		Enabled: true,
+		Status:  apicaps.CapStatusExperimental,
+	})
 }