Update shells/bash from 5.2.12 to 5.2.15 by adding the 3 most
recent releases patches, which fix:

Patch-13:
Bash can leak memory when referencing a noneexistent
associative array element.

Patch-14:
Bash defers processing additional terminating signals when
running the EXIT trap while exiting due to a terminating signal.
This patch allows the new terminating signal to kill the shell
immediately.

Patch-15:
There are several cases where bash is too aggressive when
optimizing out forks in subshells. For example, `eval' and
traps should never be optimized.

(kre)