elementary Calendar hardcoded when launching dates

### What Happened?

I was purging some packages that I don't personally use. I left the io.elementary.calendar flatpak in place but removed maya. I expected double clicking an event would open my default calendar which is via Evolution. It did not, rather tossing an error about io.elementary.calendar not in $PATH.

Nowhere that I can find is it mentioned that a standard system package is a dependency of a flatpak? And there is zero indication that this was the issue. Solved it by trial and error.

### Steps to Reproduce

apt --purge autoremove maya-cal*

try to double click event on right side of drop down calendar on top bar

### Expected Behavior

Expected it to open Evolution.

### OS Version

8.x (Circe)

### Session Type

Classic Session (X11, This is the default)

### Software Version

Latest release (I have run all updates)

### Log Output

```shell
Program ‘io.elementary.calendar’ not found in $PATH
```

### Hardware Info

System:
Host: homewrecker Kernel: 6.11.0-17-generic arch: x86_64 bits: 64
Desktop: Pantheon v: N/A Distro: elementary OS 8 circe
Machine:
Type: Desktop System: NCSTECH product: CT1-A402 v: N/A serial: 2108-261701
Mobo: ASUSTeK model: P8H61-M LE/CSM v: Rev x.0x serial: 110204320000066
BIOS: American Megatrends v: 4501 date: 05/10/2013
CPU:
Info: quad core Intel Core i7-3770 [MT MCP] speed (MHz): avg: 1626
min/max: 1600/3900
Graphics:
Device-1: AMD Ellesmere [Radeon RX 470/480/570/570X/580/580X/590]
driver: amdgpu v: kernel
Device-2: Sunplus Innovation SPCA2281 Web Camera
driver: snd-usb-audio,uvcvideo type: USB
Display: server: X.Org v: 21.1.11 with: Xwayland v: 23.2.6 driver: X:
loaded: amdgpu unloaded: fbdev,modesetting,vesa dri: radeonsi gpu: amdgpu
resolution: 1920x1080~60Hz
API: OpenGL v: 4.6 compat-v: 4.5 vendor: amd mesa
v: 24.2.8-1ubuntu1~24.04.1 renderer: AMD Radeon RX 570 Series (radeonsi
polaris10 LLVM 19.1.1 DRM 3.59 6.11.0-17-generic)
Network:
Device-1: Realtek RTL8111/8168/8211/8411 PCI Express Gigabit Ethernet
driver: r8169
Device-2: D-Link 802.11ac NIC driver: rtw_8822bu type: USB
Drives:
Local Storage: total: 2.05 TiB used: 47.12 GiB (2.2%)
Info:
Memory: total: 16 GiB available: 15.58 GiB used: 2.15 GiB (13.8%)
Processes: 317 Uptime: 9m Shell: Sudo inxi: 3.3.34