The LT_INIT() call in configure.ac is effectively a no-op because it is preceded by a call to AC_PROG_LIBTOOL(), which is the previous name of LT_INIT() used in older libtool versions. Replace AC_PROG_LIBTOOL() with AC_PATH_PROG() to look for libtool in PATH without initializing it, which is the originally intended behavior.
Without this change, --enable-static is used by default, which causes a plain ./configure invocation to fail because static linking is now disallowed. Drop --disable-static from the ./configure invocations used in GitLab CI to test this scenario continuously.
Closes #1970 (closed)