Meta: Set 'pipefail' option correctly in shell scripts

This needs '-o' to work correctly. Also update the shebang to bash in
some scripts as shellcheck was complaining about pipefail not being a
POSIX shell thing otherwise.

Meta/lint-shell-scripts.sh

@@ -1,5 +1,6 @@
 #!/bin/bash
-set -e pipefail
+
+set -eo pipefail
 
 script_path=$(cd -P -- "$(dirname -- "$0")" && pwd -P)
 cd "$script_path/.."