matrix: Speed up buddy search

hash the matrix id and compare the number instead of comparing
the matrix id string everytime
7 jobs for wip/sadiq/matrix-fixes in 8 minutes and 27 seconds
Status Job ID Name Coverage
  Build
passed #342263
librem5
build-pureos-gcc-byzantium

00:01:36

 
  Test
passed #342265
librem5
check-po

00:00:18

passed #342264
librem5
test:debian-gcc

00:01:29

23.2%
 
  Package
passed #342266
librem5
package-pureos-byzantium

00:01:44

passed #342267
librem5:arm64
package-pureos-byzantium:arm64

00:05:21

 
  Test Package
passed #342268
librem5
autopkgtest-pureos-byzantium-package

00:01:07

passed #342269
librem5
lintian-pureos-byzantium-package

00:00:39