- Remove meson conditional - no other build system is supported.

- update to 2.2.0:
* data: Add ISDv4 5285 (Lenovo ThinkPad X13 Yoga Gen 2)
* data: Add ISDv4 16C (HP ZBook x2 G4)
* Add ISDv4 52a2 (Lenovo Yoga 6 13ALC6)
* data: Add ISDv4 5218 (Lenovo IdeaPad Flex 5 14ALC05)
* data: Add ISDv4 521c (Lenovo IdeaPad Flex 5 15ALC05)
* data: Add ISDv4 49a3 (Dell Latitude 7320 Detachable)
* Remove now-unused libwacom.pc.in
* CI: add a workflow to check for "sysinfo" in newly added data files
* doc: fix the check for integration flags in the example code
* github: bump freebsd workflow to 0.1.5
* Update data/surface-go-2.tablet
* Update huion-h610-pro.tablet
* data: Add ISDv4 4995 (HP EliteBook x360 1040 G8 Notebook PC)
* data: Add ISDv4 51EF (Lenovo Yoga C740-14IML)
* data: Add ISDv4 2d1f:0095 (PINE64 PineNote)
* data: Add ISDv4 52b0 (Lenovo Yoga 7 14ACN6)
* data: Add ISDv4 511a (Lenovo ThinkPad X1 Tablet Gen 3)
* data: Add ISDv4 484d (Dell Latitude 5290)
* Add description for elan-2a70 (#466)
* data: remove unknown BuiltIn key from the DTU1931
* data: Add ISDv4 5276 (Lenovo ThinkPad X1 Yoga Gen 6)
* data: Add ISDv4 51d0 ("Lenovo ThinkPad X1 Titanium Gen 1")
* data: Add ISDv4 5019 (Fujitsu LIFEBOOK T935)
* test: add a test for matching the button count with the evdev codes
* meson.build: use gnu_symbol_visibility argument
* meson.build: use current_source_dir() over deprecated source_root()
* Remove unused arguments from two helper functions