Replace deprecated File#exists? with File#exist? for ruby >= 3.2

[Vinnehboom]

For any projects built with a ruby version of 3.2.0 or higher, the cap setup command will fail with the following error:

... 
      01 CREATE DATABASE
    ✔ 01 ubuntu@15.188.115.192 0.604s
00:01 postgresql:generate_database_yml_archetype
      01 mkdir -pv /home/ubuntu/projects/office_hardware_management/staging/db
      01 mkdir: created directory '/home/ubuntu/projects/office_hardware_management/staging/db'
    ✔ 01 ubuntu@15.188.115.192 0.101s
#<Thread:0x000000010968f7e0 /Users/vinnie-bp/.rbenv/versions/3.2.1/lib/ruby/gems/3.2.0/gems/sshkit-1.21.4/lib/sshkit/runners/parallel.rb:10 run> terminated with exception (report_on_exception is true):
/Users/vinnie-bp/.rbenv/versions/3.2.1/lib/ruby/gems/3.2.0/gems/sshkit-1.21.4/lib/sshkit/runners/parallel.rb:15:in `rescue in block (2 levels) in execute': Exception while executing as ubuntu@15.188.115.192: undefined method `exists?' for File:Class (SSHKit::Runner::ExecuteError)
        from /Users/vinnie-bp/.rbenv/versions/3.2.1/lib/ruby/gems/3.2.0/gems/sshkit-1.21.4/lib/sshkit/runners/parallel.rb:11:in `block (2 levels) in execute'
/Users/vinnie-bp/.rbenv/versions/3.2.1/lib/ruby/gems/3.2.0/gems/capistrano-postgresql-6.2.0/lib/capistrano/postgresql/helper_methods.rb:50:in `pg_template': undefined method `exists?' for File:Class (NoMethodError)

          if File.exists?(config_file) # If there is a customized file in your rails app template directory, use it and convert any ERB
                 ^^^^^^^^
Did you mean?  exist?
        from /Users/vinnie-bp/.rbenv/versions/3.2.1/lib/ruby/gems/3.2.0/gems/capistrano-postgresql-6.2.0/lib/capistrano/tasks/postgresql.rake:127:in `block (3 levels) in <top (required)>'
        from /Users/vinnie-bp/.rbenv/versions/3.2.1/lib/ruby/gems/3.2.0/gems/sshkit-1.21.4/lib/sshkit/backends/abstract.rb:31:in `instance_exec'
        from /Users/vinnie-bp/.rbenv/versions/3.2.1/lib/ruby/gems/3.2.0/gems/sshkit-1.21.4/lib/sshkit/backends/abstract.rb:31:in `run'
        from /Users/vinnie-bp/.rbenv/versions/3.2.1/lib/ruby/gems/3.2.0/gems/sshkit-1.21.4/lib/sshkit/runners/parallel.rb:12:in `block (2 levels) in execute'
(Backtrace restricted to imported tasks)
cap aborted!
SSHKit::Runner::ExecuteError: Exception while executing as ubuntu@15.188.115.192: undefined method `exists?' for File:Class


Caused by:
NoMethodError: undefined method `exists?' for File:Class

Tasks: TOP => postgresql:generate_database_yml_archetype

The ruby changelogs refer to the deprecation of the #exists? method.

We can use the alias #exist? (ref)

[tomprats]

Works for me! Sorry, was thinking I had write access for a second

[NorseGaud]

@tomprats , I can't help maintain this anymore due to other engagements. I've sent you an invite to have write access.

[tomprats]

Thank you for your previous work on this, really appreciate it!