compose: remove name key for v1 compatibility

Signed-off-by: Lakshya Singh <lakshay.singh1108@gmail.com>

docker-compose.mainnet.yml

@@ -1,5 +1,4 @@
 version: "3.8"
-name: main
 services:
   bitcoin-core:
     container_name: bitcoind-main

docker-compose.regtest.yml

@@ -1,5 +1,4 @@
 version: "3.8"
-name: regtest
 services:
   bitcoin-core:
     container_name: bitcoind-regtest

docker-compose.testnet.yml

@@ -1,5 +1,4 @@
 version: "3.8"
-name: testnet
 services:
   bitcoin-core:
     ports: