Add shellcheck to the CI

Updates our scripts to pass. Achieves POSIX compliance for
`increase_default_stack_size.sh` via replacing `hexdump` with `od` and `tr`.
Replaces the non-POSIX `dd status=none` with the POSIX `dd 2> /dev/null`.

orchestration/dev/networks/bitcoin/run.sh

@@ -1,9 +1,10 @@
 #!/bin/sh
+set -e
 
 RPC_USER="${RPC_USER:=serai}"
 RPC_PASS="${RPC_PASS:=seraidex}"
 
 bitcoind -regtest --port=8333 \
-  -rpcuser=$RPC_USER -rpcpassword=$RPC_PASS \
+  -rpcuser="$RPC_USER" -rpcpassword="$RPC_PASS" \
   -rpcbind=0.0.0.0 -rpcallowip=0.0.0.0/0 -rpcport=8332 \
-  $@
+  "$@"

orchestration/dev/networks/ethereum/run.sh

@@ -1,3 +1,4 @@
 #!/bin/sh
+set -e
 
 ~/.foundry/bin/anvil --host 0.0.0.0 --no-cors --no-mining --slots-in-an-epoch 32 --silent

orchestration/dev/networks/monero-wallet-rpc/run.sh

@@ -1,4 +1,5 @@
 #!/bin/sh
+set -e
 
 monero-wallet-rpc \
   --allow-mismatched-daemon-version \

orchestration/dev/networks/monero/run.sh

@@ -1,4 +1,5 @@
 #!/bin/sh
+set -e
 
 RPC_USER="${RPC_USER:=serai}"
 RPC_PASS="${RPC_PASS:=seraidex}"
@@ -7,5 +8,5 @@ RPC_PASS="${RPC_PASS:=seraidex}"
 monerod --non-interactive --regtest --offline --fixed-difficulty=1 \
   --no-zmq --rpc-bind-ip=0.0.0.0 --rpc-bind-port=18081 --confirm-external-bind \
   --rpc-access-control-origins "*" --disable-rpc-ban \
-  --rpc-login=$RPC_USER:$RPC_PASS --log-level 2 \
-  $@
+  --rpc-login="$RPC_USER":"$RPC_PASS" --log-level 2 \
+  "$@"

orchestration/dev/serai/run.sh

@@ -1,3 +1,5 @@
 #!/bin/sh
+set -e
 
-serai-node --unsafe-rpc-external --rpc-cors all --chain local --$SERAI_NAME
+${SERAI_NAME:?} # Ensure this is present in the environment
+serai-node --unsafe-rpc-external --rpc-cors all --chain local --"$SERAI_NAME"