treewide: fix dangling SONAME symlinks when using ABI_VERSION

treewide: fix dangling SONAME symlinks when using ABI_VERSION

A previous commit attempted to introduce proper SONAME symlinks for
packages utilizing ABI_VERSION. However, it incorrectly copied only
the symlink without the underlying physical library file, resulting
in broken packages with dangling symlinks.

Before:
```
tar -Oxzf bin/packages/arm_cortex-a9_vfpv3-d16/packages/oniguruma_6.9.9-r1_arm_cortex-a9_vfpv3-d16.ipk ./data.tar.gz | tar -tzvf -
drwxr-xr-x  0 0      0           0 Feb  5  2024 ./
drwxr-xr-x  0 0      0           0 Feb  5  2024 ./usr/
drwxr-xr-x  0 0      0           0 Feb  5  2024 ./usr/lib/
lrwxrwxrwx  0 0      0           0 Feb  5  2024 ./usr/lib/libonig.so.5 -> libonig.so.5.4.0
```

After:
```
tar -Oxzf bin/packages/arm_cortex-a9_vfpv3-d16/packages/oniguruma_6.9.9-r1_arm_cortex-a9_vfpv3-d16.ipk ./data.tar.gz | tar -tzvf -
drwxr-xr-x  0 0      0           0 Feb  5  2024 ./
drwxr-xr-x  0 0      0           0 Feb  5  2024 ./usr/
drwxr-xr-x  0 0      0           0 Feb  5  2024 ./usr/lib/
lrwxrwxrwx  0 0      0           0 Feb  5  2024 ./usr/lib/libonig.so.5 -> libonig.so.5.4.0
-rwxr-xr-x  0 0      0      526493 Feb  5  2024 ./usr/lib/libonig.so.5.4.0
```

This properly standardizes shared library packaging, prevents shipping
duplicate full-sized files (as seen previously in packages like libre2),
and aligns the packages feed with core OpenWrt practices.
As you could see in the previous commit (see it in the ``Fixes`` tag):

Before:
```
tar -Oxzf bin/packages/arm_cortex-a9_vfpv3-d16/packages/re2_2023.02.01\~b025c6a3-r1_arm_cortex-a9_vfpv3-d16.ipk ./data.tar.gz | tar -tzvf -
drwxr-xr-x  0 0      0           0 Aug 18  2024 ./
drwxr-xr-x  0 0      0           0 Aug 18  2024 ./usr/
drwxr-xr-x  0 0      0           0 Aug 18  2024 ./usr/lib/
-rw-r--r--  0 0      0      331875 Aug 18  2024 ./usr/lib/libre2.so
-rw-r--r--  0 0      0      331875 Aug 18  2024 ./usr/lib/libre2.so.10
-rw-r--r--  0 0      0      331875 Aug 18  2024 ./usr/lib/libre2.so.10.0.0
```

After:
```
tar -Oxzf bin/packages/arm_cortex-a9_vfpv3-d16/packages/re2_2023.02.01\~b025c6a3-r1_arm_cortex-a9_vfpv3-d16.ipk ./data.tar.gz | tar -tzvf -
drwxr-xr-x  0 0      0           0 Aug 18  2024 ./
drwxr-xr-x  0 0      0           0 Aug 18  2024 ./usr/
drwxr-xr-x  0 0      0           0 Aug 18  2024 ./usr/lib/
lrwxrwxrwx  0 0      0           0 Aug 18  2024 ./usr/lib/libre2.so -> libre2.so.10
lrwxrwxrwx  0 0      0           0 Aug 18  2024 ./usr/lib/libre2.so.10 -> libre2.so.10.0.0
-rwxr-xr-x  0 0      0      331875 Aug 18  2024 ./usr/lib/libre2.so.10.0.0
```

Fixes: 537c2a631dd117564720a80f6976280901b010f5 ("treewide: avoid deref symlinks when installing .so")
Signed-off-by: Josef Schlehofer <redacted>