The current version of murmur is 1.4.230-6 which specifically depends on grpc 1.45.2-3 and protobuf 3.20.1-2, which are not in repos anymore.
$this->bbcode_second_pass_code('', 'pacman -Qi murmur
Name : murmur
Version : 1.4.230-6
Description : An Open Source, low-latency, high quality voice chat software (server)
Architecture : aarch64
URL : https://www.mumble.info/
Licenses : BSD
Groups : None
Provides : None
Depends On : gcc-libs glibc openssl qt5-base avahi libcap.so=2-64 libdns_sd.so=1-64 libgrpc++.so=1.45-64 libprotobuf.so=31-64 zeroc-ice
Optional Deps : None
Required By : None
Optional For : None
Conflicts With : None
Replaces : None
Installed Size : 4.38 MiB
Packager : Arch Linux ARM Build System <builder+n1@archlinuxarm.org>
Build Date : Sat May 14 23:37:51 2022
Install Date : Thu May 19 14:48:44 2022
Install Reason : Explicitly installed
Install Script : Yes
Validated By : Signature')
The current version of grpc provides libgrpc++.so.1.48, and protobuf provides libprotobuf.so.32. This prevents fully updating the system as grpc and protobuf can't be updated because of the versioned dependency of murmur.
EDIT: This has been solved with the murmur package being updated to version 1.4.230-13