feat: add nocache url parameter option

Signed-off-by: Scott Quinlan <scott@sitehost.co.nz>

api/prometheus/v1/api.go

@@ -1079,6 +1079,7 @@ func (h *httpAPI) LabelValues(ctx context.Context, label string, matches []strin
 type apiOptions struct {
 	timeout time.Duration
 	limit   uint64
+	nocache bool
 }
 
 type Option func(c *apiOptions)
@@ -1099,6 +1100,13 @@ func WithLimit(limit uint64) Option {
 	}
 }
 
+// WithNoCache can be used to provide an optional nocache parameter for Query and QueryRange.
+func WithNoCache() Option {
+	return func(o *apiOptions) {
+		o.nocache = true
+	}
+}
+
 func addOptionalURLParams(q url.Values, opts []Option) url.Values {
 	opt := &apiOptions{}
 	for _, o := range opts {
@@ -1113,6 +1121,10 @@ func addOptionalURLParams(q url.Values, opts []Option) url.Values {
 		q.Set("limit", strconv.FormatUint(opt.limit, 10))
 	}
 
+	if opt.nocache {
+		q.Set("nocache", "1")
+	}
+
 	return q
 }