[scripts] specify bash as program loader

https://en.wikipedia.org/wiki/Shebang_(Unix)

gdb.sh

@@ -1,3 +1,4 @@
+#!/usr/bin/env bash
 ./riscv-qemu/riscv64-softmmu/qemu-system-riscv64 -S -s -D debug.log -nographic -machine virt \
 	-secure-boot sanctum_bootloader/boot_trng.bin \
   -kernel riscv-pk/build/bbl -append "root=/dev/vda ro console=ttyS0" \

scripts/apply-patch.sh

@@ -1,3 +1,4 @@
+#!/usr/bin/env bash
 cd riscv-qemu
 patch hw/riscv/boot.c < ../patches/qemu-kernel-reloc.patch
 patch target/riscv/pmp.c < ../patches/pmp-bug.patch

scripts/debug.sh

@@ -1,3 +1,4 @@
+#!/usr/bin/env bash
 #./riscv-qemu/riscv64-softmmu/qemu-system-riscv64 -d in_asm \ #in_asm,out_asm,int,mmu,exec,cpu
 #gdb --args ./riscv-qemu/riscv64-softmmu/qemu-system-riscv64 -d in_asm -D debug.log -nographic -machine virt \
 ./riscv-qemu/riscv64-softmmu/qemu-system-riscv64 \

scripts/run-qemu.sh

@@ -1,3 +1,4 @@
+#!/usr/bin/env bash
 ./riscv-qemu/riscv64-softmmu/qemu-system-riscv64 -D debug.log -nographic -machine virt \
 	-bios sanctum_bootloader/boot_trng.elf \
   -kernel riscv-pk/build/bbl -append "root=/dev/vda ro console=ttyS0" \