stubby (getdns): needs to be compiled against WolfSSL vs OpenSSL

Maintainer: no one
Environment: (put here arch, model, OpenWrt version) 22.03.0 r19685-512e76967f , TP-Link TL-WDR3600 v1.

Description: stubby is compiled against libopenssl1.1 which is a very big package. After installing just two packages on my device, stubby and sudo, I now have just 156KB of free space which is horrible.

# opkg install stubby
Installing stubby (0.4.0-6) to root...
Downloading https://downloads.openwrt.org/releases/22.03.0/packages/mips_24kc/packages/stubby_0.4.0-6_mips_24kc.ipk
Installing libyaml (0.2.5-1) to root...
Downloading https://downloads.openwrt.org/releases/22.03.0/packages/mips_24kc/packages/libyaml_0.2.5-1_mips_24kc.ipk
Installing libopenssl1.1 (1.1.1q-1) to root...
Downloading https://downloads.openwrt.org/releases/22.03.0/packages/mips_24kc/base/libopenssl1.1_1.1.1q-1_mips_24kc.ipk
Installing getdns (1.7.0-2) to root...
Downloading https://downloads.openwrt.org/releases/22.03.0/packages/mips_24kc/packages/getdns_1.7.0-2_mips_24kc.ipk
Configuring libopenssl1.1.
Configuring getdns.
Configuring libyaml.
Configuring stubby.

# opkg install sudo
Installing sudo (1.9.10-1) to root...
Downloading https://downloads.openwrt.org/releases/22.03.0/packages/mips_24kc/packages/sudo_1.9.10-1_mips_24kc.ipk
Configuring sudo.

# df /
Filesystem           1K-blocks      Used Available Use% Mounted on
overlayfs:/overlay        2112      1956       156  93% /

I guess this is an upstream issue but I'll leave it here anyways: https://github.com/getdnsapi/stubby/issues/311

Start by reading the linked upstream getdns/stubby issue #311, then inspect the OpenWrt package definitions and dependency metadata for stubby and getdns. The work is complete when the packages can use WolfSSL instead of libopenssl1.1 and installation no longer pulls in that large OpenSSL dependency.