Problems with updating PHP through terminal, "unsatisfiable constraints" error appears

[CDMacalister]

The admin dashboard for my Instant WP informs me I should update PHP.

I have followed the instructions supplied by Instant WP's FAQ on doing this, with the following two commands in succession --

sudo apk update

sudo apk upgrade

The result is an "unsatisfiable constraints" error, specifically the following --

WARNING: This apk-tools is OLD! Some packages might not function properly. ERROR: unsatisfiable constraints: so:libargon2.so.1 (missing): required by: php7-phpdbg-7.4.19-r0[so:libargon2.so.1] php7-embed-7.4.19-r0[so:libargon2.so.1] php7-7.4.19-r0[so:libargon2.so.1] php7-cgi-7.4.19-r0[so:libargon2.so.1] php7-7.4.19-r0[so:libargon2.so.1] php7-embed-7.4.19-r0[so:libargon2.so.1] php7-7.4.19-r0[so:libargon2.so.1] php7-phpdbg-7.4.19-r0[so:libargon2.so.1] php7-7.4.19-r0[so:libargon2.so.1] php7-cgi-7.4.19-r0[so:libargon2.so.1] php7-cgi-7.4.19-r0[so:libargon2.so.1] php7-apache2-7.4.19-r0[so:libargon2.so.1] php7-cgi-7.4.19-r0[so:libargon2.so.1] php7-apache2-7.4.19-r0[so:libargon2.so.1] php7-7.4.19-r0[so:libargon2.so.1] php7-7.4.19-r0[so:libargon2.so.1] php7-phpdbg-7.4.19-r0[so:libargon2.so.1] php7-embed-7.4.19-r0[so:libargon2.so.1] php7-phpdbg-7.4.19-r0[so:libargon2.so.1] so:libpcre2-8.so.0 (missing): required by: php7-phpdbg-7.4.19-r0[so:libpcre2-8.so.0] php7-embed-7.4.19-r0[so:libpcre2-8.so.0] php7-7.4.19-r0[so:libpcre2-8.so.0] php7-cgi-7.4.19-r0[so:libpcre2-8.so.0] php7-7.4.19-r0[so:libpcre2-8.so.0] php7-embed-7.4.19-r0[so:libpcre2-8.so.0] php7-7.4.19-r0[so:libpcre2-8.so.0] php7-phpdbg-7.4.19-r0[so:libpcre2-8.so.0] php7-7.4.19-r0[so:libpcre2-8.so.0] php7-cgi-7.4.19-r0[so:libpcre2-8.so.0] php7-cgi-7.4.19-r0[so:libpcre2-8.so.0] php7-apache2-7.4.19-r0[so:libpcre2-8.so.0] php7-cgi-7.4.19-r0[so:libpcre2-8.so.0] php7-apache2-7.4.19-r0[so:libpcre2-8.so.0] php7-7.4.19-r0[so:libpcre2-8.so.0] php7-7.4.19-r0[so:libpcre2-8.so.0] php7-phpdbg-7.4.19-r0[so:libpcre2-8.so.0] php7-embed-7.4.19-r0[so:libpcre2-8.so.0] php7-phpdbg-7.4.19-r0[so:libpcre2-8.so.0] so:libgdbm.so.6 (missing): required by: php7-dba-7.4.19-r0[so:libgdbm.so.6] php7-dba-7.4.19-r0[so:libgdbm.so.6] so:liblmdb.so.0 (missing): required by: php7-dba-7.4.19-r0[so:liblmdb.so.0] php7-dba-7.4.19-r0[so:liblmdb.so.0] pcre2-dev (missing): required by: php7-dev-7.4.19-r0[pcre2-dev] php7-dev-7.4.19-r0[pcre2-dev] php7-dev-7.4.19-r0[pcre2-dev] php7-dev-7.4.19-r0[pcre2-dev] php7-dev-7.4.19-r0[pcre2-dev] so:libicuuc.so.67 (missing): required by: nuspell-4.2.0-r0[so:libicuuc.so.67] enchant2-2.2.15-r0[so:libicuuc.so.67] enchant2-2.2.15-r0[so:libicuuc.so.67] enchant2-2.2.15-r0[so:libicuuc.so.67] nuspell-4.2.0-r0[so:libicuuc.so.67] enchant2-2.2.15-r0[so:libicuuc.so.67] nuspell-4.2.0-r0[so:libicuuc.so.67] so:libcrypto.so.1.1 (missing): required by: php7-openssl-7.4.19-r0[so:libcrypto.so.1.1] php7-openssl-7.4.19-r0[so:libcrypto.so.1.1] libzip-1.7.3-r2[so:libcrypto.so.1.1] php7-ftp-7.4.19-r0[so:libcrypto.so.1.1] libzip-1.7.3-r2[so:libcrypto.so.1.1] php7-ftp-7.4.19-r0[so:libcrypto.so.1.1] so:libssl.so.1.1 (missing): required by: php7-openssl-7.4.19-r0[so:libssl.so.1.1] php7-openssl-7.4.19-r0[so:libssl.so.1.1] php7-ftp-7.4.19-r0[so:libssl.so.1.1] php7-ftp-7.4.19-r0[so:libssl.so.1.1] so:libnetsnmp.so.40 (missing): required by: php7-snmp-7.4.19-r0[so:libnetsnmp.so.40] php7-snmp-7.4.19-r0[so:libnetsnmp.so.40]

What am I to make of this, and what do I do next?

P.S. Assuming it matters, sudo apk update -- before typing in the second command -- results in the following --

fetch http://dl-cdn.alpinelinux.org/alpine/v3.6/main/x86/APKINDEX.tar.gz fetch http://dl-cdn.alpinelinux.org/alpine/edge/community/x86/APKINDEX.tar.gz WARNING: This apk-tools is OLD! Some packages might not function properly. v3.6.5-44-gda55e27396 [http://dl-cdn.alpinelinux.org/alpine/v3.6/main] v20210212-7135-g6053fa3b93 [http://dl-cdn.alpinelinux.org/alpine/edge/community] OK: 15405 distinct packages available