update_version script is broken

[conorsch]

Description

The ./update_version.sh script in the repository is broken.

Steps to Reproduce

Run the script with a fake version:

./update_version.sh 1.8.4

Expected Behavior

Script updates all necessary targets, exits without error.

Actual Behavior

Script fails, complaining about a missing file:

$ ./update_version.sh 1.8.4
sed: can't read install_files/securedrop-app-code/debian/control: No such file or directory

Comments

Looks like the changes in #5465 broke it. We'll need to resolve prior to bumping to 1.6.0~rc2, and the fix should land in both develop and release/1.6.0 branches.