Enable slow extensions

PDO_sqlite, the Pg extensions, SNMP, LDAP, Enchant, Tidy, ODBC, and
PDO_DBLIB. Note that DBLIB and ODBC will be hard to test since the tests
assume SQL Server. LDAP and SNMP may require config on the PPC CI
server, but Pg shhould be configured and ready to go.

Author: NattyNarwhal

.github/workflows/nightly.yml

@@ -67,7 +67,7 @@ jobs:
             CXX=clang++-17
             --enable-debug
             --enable-zts
-          skipSlow: true # FIXME: This should likely include slow extensions
+          skipSlow: false # FIXME: This should likely include slow extensions
       - name: make
         run: make -j$(/usr/bin/nproc) >/dev/null
       # Skip an install action for now