Garbage collection is run after every command

### How to reproduce
```bash
❯ task list

ID Age Description Urg
1 7s test1 0
2 5s test2 0
3 3s test3 0

3 tasks
❯ task done 1
Completed task 1 'test1'.
Completed 1 task.
❯ task 3 modify priority:H
No tasks specified.
❯ task 2 modify priority:H
Modifying task 2 'test3'.
Modified 1 task.
❯ task list

ID Age P Description Urg
2 39s H test3 6
1 41s test2 0

2 tasks
```

### Expected result
According to https://taskwarrior.org/docs/ids.html renumbering of the tasks should not happen before/after every command, but only before e.g. `task list`. Task `task2` should have been modified to have priority `H`.

### Actual result
Instead renumbering occurs after `task done 1`/before `task 2 modify priority:H` and therefore `task3` now has ID `2` and gets modified instead.

### Diag
```bash
❯ task diag

task 2.6.2
Platform: Linux

Compiler
Version: 11.2.0
Caps: +stdc +stdc_hosted +LP64 +c8 +i32 +l64 +vp64 +time_t64
Compliance: C++17

Build Features
CMake: 3.22.3
libuuid: libuuid + uuid_unparse_lower
libgnutls: 3.7.3
Build type:

Configuration
File: /home/user/.taskrc (found), 1400 bytes, mode 100644
Data: /home/user/.task (found), dir, mode 40755
Locking: Enabled
GC: Enabled
$EDITOR: /usr/bin/vim
Server:
CA: -
Certificate: -
Key: -
Trust: strict
Ciphers: NORMAL
Creds:

Hooks
System: Enabled
Location: /home/user/.task/hooks
(-none-)

Tests
Terminal: 120x30
Dups: Scanned 53 tasks for duplicate UUIDs:
No duplicates found
Broken ref: Scanned 53 tasks for broken references:
No broken references found
```