testing/libstemmer: new aport

The included patch for enabling dynamic lib is an upstream issue:
https://github.com/snowballstem/snowball/issues/34
7 jobs for !13991 with libstemmer in 2 minutes and 25 seconds
detached
Status Job ID Name Coverage
  Lint
passed #236151
x86_64 docker-alpine
lint

00:00:24

 
  Build
passed #236156
aarch64 ci-build docker-alpine
build-aarch64

00:01:19

passed #236157
armv7 ci-build docker-alpine
build-armv7

00:01:08

passed #236155
ppc64le ci-build docker-alpine
build-ppc64le

00:01:06

passed #236154
s390x ci-build docker-alpine
build-s390x

00:00:30

passed #236153
x86 ci-build docker-alpine
build-x86

00:00:28

passed #236152
x86_64 ci-build docker-alpine
build-x86_64

00:00:32