Suppress Pry history loading only if Pry is already defined

[dwelch-r7]

Here's your PR description:

---

Description

Defer Pry loading in Rex::Ui::Text::Shell#run to avoid paying the require 'pry' cost on every msfconsole boot. Saves about 0.2s on my machine.

The run method previously did an unconditional require 'pry' solely to set Pry.config.history_load = false — a config that prevents Pry from loading its own history when binding.pry is used. This loaded the entire Pry gem at boot even though most sessions never use Pry.

The change replaces require 'pry' with if defined?(Pry), which only sets the config when Pry has already been loaded elsewhere.

Verification Steps

1. • Start msfconsole normally — verify it boots without errors
2. • Run the pry command inside msfconsole — verify Pry session starts and Pry history isn't polluted with framework commands

Test Evidence

# Before (with require 'pry' at boot):
hyperfine  --warmup 3 "bundle exec ruby ./msfconsole -q -x 'exit'"                                                                                                                                                        
Benchmark 1: bundle exec ruby ./msfconsole -q -x 'exit'
  Time (mean ± σ):      4.337 s ±  0.080 s    [User: 3.055 s, System: 1.351 s]
  Range (min … max):    4.237 s …  4.485 s    10 runs

# After
hyperfine  --warmup 3 "bundle exec ruby ./msfconsole -q -x 'exit'"                                                                                                                                                        
Benchmark 1: bundle exec ruby ./msfconsole -q -x 'exit'
  Time (mean ± σ):      4.155 s ±  0.058 s    [User: 2.986 s, System: 1.272 s]
  Range (min … max):    4.048 s …  4.232 s    10 runs

Environment

Field	Details
Operating System	macOS (26.5.2)
Ruby version	3.3.8

AI Usage Disclosure

Kiro

Pre-Submission Checklist

• No sensitive information (IP addresses, credentials, API keys, hashes) in code or documentation
• Tested on the target environment specified in the Environment section above
• Read the CONTRIBUTING.md and module acceptance guidelines