cmake does not build curl.1

### I did this

`cmake -Bbuild . && make -C build -j9`

This builds the man pages in build/docs/libcurl/ but not  build/docs/curl.1  build/docs/curl-config.1 or build/docs/mk-ca-bundle.1  This causes tests 1140 and 1173 to fail.

### I expected the following

All the man pages should be built by cmake.

### curl/libcurl version

curl-8.7.0-DEV commit 9e2ee7049

### operating system

Linux x86_64