`platform process list` output grows indefinitely with duplicate entries

[andrurogerz]

Each time you run platform process list from lldb when connected to a remote ds2 server, the list gets longer and contains duplicate entries.

For example, on Android:

(lldb) platform connect connect://localhost:5432
  Platform: remote-android
    Triple: x86_64-unknown-linux-android
OS Version: 34 (6.1.23-android14-4-00257-g7e35917775b8-ab9964412)
  Hostname: localhost
 Connected: yes
WorkingDir: /
    Kernel: #1 SMP PREEMPT Mon Apr 17 20:50:58 UTC 2023
(lldb) platform process list
3 matching processes were found on "remote-android"

PID    PARENT USER       TRIPLE                         NAME
====== ====== ========== ============================== ============================
190    1      shell      x86_64-unknown-linux-android   sh
6335   456    shell      x86_64-unknown-linux-android   sh
10451  6335   shell      x86_64-unknown-linux-android   ds2
(lldb) platform process list
6 matching processes were found on "remote-android"

PID    PARENT USER       TRIPLE                         NAME
====== ====== ========== ============================== ============================
190    1      shell      x86_64-unknown-linux-android   sh
6335   456    shell      x86_64-unknown-linux-android   sh
10451  6335   shell      x86_64-unknown-linux-android   ds2
190    1      shell      x86_64-unknown-linux-android   sh
6335   456    shell      x86_64-unknown-linux-android   sh
10451  6335   shell      x86_64-unknown-linux-android   ds2
(lldb) platform process list
9 matching processes were found on "remote-android"

PID    PARENT USER       TRIPLE                         NAME
====== ====== ========== ============================== ============================
190    1      shell      x86_64-unknown-linux-android   sh
6335   456    shell      x86_64-unknown-linux-android   sh
10451  6335   shell      x86_64-unknown-linux-android   ds2
190    1      shell      x86_64-unknown-linux-android   sh
6335   456    shell      x86_64-unknown-linux-android   sh
10451  6335   shell      x86_64-unknown-linux-android   ds2
190    1      shell      x86_64-unknown-linux-android   sh
6335   456    shell      x86_64-unknown-linux-android   sh
10451  6335   shell      x86_64-unknown-linux-android   ds2
(lldb) platform process list
12 matching processes were found on "remote-android"

PID    PARENT USER       TRIPLE                         NAME
====== ====== ========== ============================== ============================
190    1      shell      x86_64-unknown-linux-android   sh
6335   456    shell      x86_64-unknown-linux-android   sh
10451  6335   shell      x86_64-unknown-linux-android   ds2
190    1      shell      x86_64-unknown-linux-android   sh
6335   456    shell      x86_64-unknown-linux-android   sh
10451  6335   shell      x86_64-unknown-linux-android   ds2
190    1      shell      x86_64-unknown-linux-android   sh
6335   456    shell      x86_64-unknown-linux-android   sh
10451  6335   shell      x86_64-unknown-linux-android   ds2
190    1      shell      x86_64-unknown-linux-android   sh
6335   456    shell      x86_64-unknown-linux-android   sh
10451  6335   shell      x86_64-unknown-linux-android   ds2