Add avahi to an acceptable spellcheck word

[andy31415]

Problem

ToT spellcheck fails (even though it passed before I merged the corresponding PR)

Change overview

Adds avahi to the .wordlist.txt file

Testing

CI will validate, but realistically very safe change.

[github-actions]

PR #13342: Size comparison from 6f5dd37 to 1e5b89e

Full report (14 builds for efr32, k32w, linux, p6, qpg, telink)

platform	target	config	section	6f5dd37	1e5b89e	change	% change
efr32	lighting-app	BRD4161A	(read only)	829396	829396	0	0.0
			(read/write)	127068	127068	0	0.0
			.bss	125192	125192	0	0.0
			.data	1876	1876	0	0.0
			.text	829388	829388	0	0.0
		BRD4161A+rpc	(read only)	816576	816576	0	0.0
			(read/write)	143736	143736	0	0.0
			.bss	141760	141760	0	0.0
			.data	1976	1976	0	0.0
			.text	816568	816568	0	0.0
	window-app	BRD4161A	(read only)	802844	802844	0	0.0
			(read/write)	126008	126008	0	0.0
			.bss	124176	124176	0	0.0
			.data	1832	1832	0	0.0
			.text	802836	802836	0	0.0
k32w	light	k32w061+release	(read/write)	648472	648472	0	0.0
			.bss	76216	76216	0	0.0
			.data	1904	1904	0	0.0
			.text	564552	564552	0	0.0
	lock	k32w061+release	(read/write)	633296	633296	0	0.0
			.bss	75928	75928	0	0.0
			.data	1860	1860	0	0.0
			.text	549708	549708	0	0.0
linux	chip-tool-ipv6only	arm64	(read only)	7011468	7011468	0	0.0
			(read/write)	324849	324849	0	0.0
			.bss	54209	54209	0	0.0
			.data	1096	1096	0	0.0
			.data.rel.ro	208968	208968	0	0.0
			.dynamic	560	560	0	0.0
			.got	56888	56888	0	0.0
			.init	24	24	0	0.0
			.init_array	168	168	0	0.0
			.rodata	383108	383108	0	0.0
			.text	5936084	5936084	0	0.0
	thermostat-no-ble	arm64	(read only)	2024348	2024348	0	0.0
			(read/write)	144049	144049	0	0.0
			.bss	64001	64001	0	0.0
			.data	880	880	0	0.0
			.data.rel.ro	72296	72296	0	0.0
			.dynamic	560	560	0	0.0
			.got	3936	3936	0	0.0
			.init	24	24	0	0.0
			.init_array	296	296	0	0.0
			.rodata	128524	128524	0	0.0
			.text	1683152	1683152	0	0.0
p6	all-clusters-app	default	(read/write)	2401288	2401288	0	0.0
			.bss	116748	116748	0	0.0
			.data	2592	2592	0	0.0
			.text	1359552	1359552	0	0.0
	light-app	default	(read/write)	2324568	2324568	0	0.0
			.bss	105872	105872	0	0.0
			.data	2384	2384	0	0.0
			.text	1282832	1282832	0	0.0
	lock-app	default	(read/write)	2296768	2296768	0	0.0
			.bss	104752	104752	0	0.0
			.data	2336	2336	0	0.0
			.text	1255032	1255032	0	0.0
qpg	lighting-app	qpg6105+debug	(read only)	531664	531664	0	0.0
			(read/write)	146936	146936	0	0.0
			.bss	86672	86672	0	0.0
			.data	1004	1004	0	0.0
			.text	526344	526344	0	0.0
	lock-app	qpg6105+debug	(read only)	503444	503444	0	0.0
			(read/write)	146940	146940	0	0.0
			.bss	85808	85808	0	0.0
			.data	952	952	0	0.0
			.text	498124	498124	0	0.0
	persistent-storage-app	qpg6105+debug	(read only)	106448	106448	0	0.0
			(read/write)	146938	146938	0	0.0
			.bss	36146	36146	0	0.0
			.data	288	288	0	0.0
			.text	101128	101128	0	0.0
telink	lighting-app	tlsr9518adk80d	(read/write)	832242	832242	0	0.0
			bss	86856	86856	0	0.0
			noinit	37160	37160	0	0.0
			text	580682	580682	0	0.0