Add configurable timeout to netcat calls with 10s default

[mati865]

Description of the change

Without any timeout, netcat can get stuck forever (until Kubernetes kills unhealthy Pod) when configured address and port combination is wrong, or the connection gets stuck.
For example nc -z bitnami.com 12345 doesn't seem to ever finish.

Benefits

In the case when an attempt gets stuck, the timeout will allow further attempts to be performed, instead of waiting until Pod is killed.

Possible drawbacks

When the timeout is too short, valid configurations might falsely show as broken. Thus, I chose 10s which should be long enough.

Applicable issues

Additional information

Default 10s timeout is very conservative and should not cause spurious failures, users are advised to shorten it according to their needs.

[gongomgra]

@mati865 thanks for your contribution! What do you think about adding a new parameter to the <asset>-env.sh file for this new setting?

[mati865]

@gongomgra I considered this from the beginning, but opted for an easy fix/workaround to avoid spending too much time investigating the scripts' interdependencies.

If this is just a matter of adding it to one more script per chart, I can certainly look into that.

[gongomgra]

@mati865 you can take a look to a recent PR for pgbouncer adding a new environment variable definition at #75939

[mati865]

@gongomgra thank you for the pointers, updated commit, description and title. The diff of the changes since your initial review is available at: https://github.com/bitnami/containers/compare/3d664506660480823bbcc01c6582e3256f038a0b..fe39acaf1defd3c57b5d7a3c9d287d32d7315447
The second force-push is for commit name because I forgot to update it.

I have used 10s as the default value, so this change is backwards compatible.

[gongomgra]

Thanks for your contribution!