The actual error seems to be
Stderr: Installing grub to /boot/efi. Installing for x86_64-efi platform. grub-install: warning: Cannot set EFI variable BootOrder. grub-install: warning: efivarfs_set_variable: writing to fd 9 failed: Read-only file system. grub-install: warning: _efi_set_variable_mode: ops->set_variable() failed: Read-only file system. grub-install: error: failed to register the EFI boot entry: Read-only file system.
The actual error seems to be
Stderr: Installing grub to /boot/efi.
Installing for x86_64-efi platform.
grub- install: warning: Cannot set EFI variable BootOrder.
grub- install: warning: efivarfs_ set_variable: writing to fd 9 failed: Read-only file system.
grub- install: warning: _efi_set_ variable_ mode: ops->set_variable() failed: Read-only file system.
grub- install: error: failed to register the EFI boot entry: Read-only file system.