Find shell files based on file content, not extension, and run shellcheck for CICD

find_and_check_shell_files.sh

#!/bin/bash

# finds every file in the directory specified starting with '#!' and ending with 'bash' on the same line
# i.e. #!/bin/bash this allows us to only shellcheck shell files, but this would
# have been a lot simpler if the shell files all had .sh extensions
# added --serverity option due to egregious output in CICD, valid values in order of severity are
# error, warning, info and style. The default is style.

for file in $(find source/legacy -type f -exec awk '/^#!.*bash/{r=1};{exit} END {exit(1-r)}' {} \; -print)
do
    shellcheck --severity=warning "$file"
done