Have max_logs able to be set from env variable with a default value of 10

[msaldivar]

How would this feature be useful?
Executing more than 10 python scripts (cicd jobs) concurrently will lead to pipx failing

Describe the solution you'd like
The current default value to max_logs is 10, this solution involves reading from an environment variable, MAX_PIPX_LOGS. If the variable is not present the current values is set to 10.

max_logs = int(os.getenv("MAX_PIPX_LOGS", 10))

Describe alternatives you've considered
Possibly allowing the value to be set by cmdline arg, however an environment variable is simpler for automated environments.