package/cloudflared: bump to version 2025.8.1

Also set BuiltForPackageManager=buildroot so that cloudflared's update
command informs the user to update cloudflared via buildroot.

Without BuiltForPackageManager set:
cloudflared update
INF cloudflared is up to date version=

With BuiltForPackageManager set:
cloudflared update
ERR cloudflared was installed by buildroot. Please update using the same method.

Signed-off-by: James Hilliard <james.hilliard1@gmail.com>
Signed-off-by: Julien Olivain <ju.o@free.fr>

package/cloudflared/cloudflared.hash

@@ -1,3 +1,3 @@
 # Locally computed
-sha256  f9223cdefaa4b75aa1c49638936af9d5007b6c7bd943ab70203bb75bf32467da  cloudflared-2025.1.0-go2.tar.gz
+sha256  803d3e162dc91da6b3b4f7961f57c113fa818d45517758511f72d254d68a46ba  cloudflared-2025.8.1-go2.tar.gz
 sha256  58d1e17ffe5109a7ae296caafcadfdbe6a7d176f0bc4ab01e12a689b0499d8bd  LICENSE

package/cloudflared/cloudflared.mk

@@ -4,12 +4,14 @@
 #
 ################################################################################
 
-CLOUDFLARED_VERSION = 2025.1.0
+CLOUDFLARED_VERSION = 2025.8.1
 CLOUDFLARED_SITE = $(call github,cloudflare,cloudflared,$(CLOUDFLARED_VERSION))
 CLOUDFLARED_LICENSE = Apache-2.0
 CLOUDFLARED_LICENSE_FILES = LICENSE
 CLOUDFLARED_CPE_ID_VENDOR = cloudflare
 CLOUDFLARED_BUILD_TARGETS = cmd/cloudflared
-CLOUDFLARED_LDFLAGS = -X main.Version=$(CLOUDFLARED_VERSION)
+CLOUDFLARED_LDFLAGS = \
+	-X main.Version=$(CLOUDFLARED_VERSION) \
+	-X github.com/cloudflare/cloudflared/cmd/cloudflared/updater.BuiltForPackageManager=buildroot
 
 $(eval $(golang-package))