LOSTANDFOUND.md: update with boards/nrf6310

Author: crasbe

LOSTANDFOUND.md

@@ -302,6 +302,18 @@ therefore, have no interest in supporting this board. As result, none of the
 RIOT core contributors has access to the hardware, preventing us from doing the
 necessary testing for maintaining this board.
 
+### boards/nrf6310 [4953ba8e6759d2b1a1a1ea497a4ad1e71489195a]
+Author(s):
+- Christian Kühling <kuehling@zedat.fu-berlin.de>
+- Timo Ziegler <timo.ziegler@fu-berlin.de>
+- Hauke Petersen <hauke.petersen@fu-berlin.de>
+
+Reason for removal:
+- this was an early development board by Nordic which was discontinued
+ (successor: `nrf51dk`)
+- also for a `BLE DEVKIT.N` board from Mommosoft, which was discontinued as well
+- no hardware available anymore for testing, many exclusions from CI
+
 [6cad5d24771ba6199228351a11b5062cd2e9b36d]: https://github.com/RIOT-OS/RIOT/commit/6cad5d24771ba6199228351a11b5062cd2e9b36d
 [d83d08f0995a88f399e70a7d07b44dd780082436]: https://github.com/RIOT-OS/RIOT/commit/d83d08f0995a88f399e70a7d07b44dd780082436
 [cdc252ab7bd4161cc046bf93a3e55995704b24d4]: https://github.com/RIOT-OS/RIOT/commit/cdc252ab7bd4161cc046bf93a3e55995704b24d4
@@ -334,3 +346,4 @@ necessary testing for maintaining this board.
 [fe941ac9fe3f81c0f08ff3b8564cf439639abcda]: https://github.com/RIOT-OS/RIOT/commit/fe941ac9fe3f81c0f08ff3b8564cf439639abcda
 [81458c8eed8949c686d5ded652dbee10748e860b]: https://github.com/RIOT-OS/RIOT/commit/81458c8eed8949c686d5ded652dbee10748e860b
 [2b8a0d48940517f7df4e78c7a0b16024f46a8694]: https://github.com/RIOT-OS/RIOT/commit/2b8a0d48940517f7df4e78c7a0b16024f46a8694
+[4953ba8e6759d2b1a1a1ea497a4ad1e71489195a]: https://github.com/RIOT-OS/RIOT/commit/4953ba8e6759d2b1a1a1ea497a4ad1e71489195a