CXX-3290 fix static pkgconfig requirements

[kevinAlbs]

Restore behavior consistent with r4.0.0. The static bsoncxx / mongocxx pkgconfig file depends on the static bson / mongoc pkg-config files:

In r4.0.0:

# In libbsoncxx-static.pc:
Version: 4.0.0
Requires: libbson-static-1.0 >= 1.29.0

In r4.1.0 (before this fix):

# In libbsoncxx-static.pc:
Version: 4.1.0
Requires: bson2 >= 2.0.0

Related: This PR does not try to resolve a discovered pre-existing issue CXX-3293 (BUILD_SHARED_LIBS_WITH_STATIC_MONGOC appears to incorrectly apply to static libraries, and is not accounted for in pkg-config files).

[eramongodb]

Suggested change

	(pkg-config --print-requires libmongocxx-static | grep -- mongoc2-static || (
	(
	echo "Expected mongoc2-static to be required" >&2
	exit 1
	)
	))
	if ! pkg-config --print-requires libmongocxx-static | grep -q "mongoc2-static"; then
	echo "Expected mongoc2-static to be required" >&2
	exit 1
	fi

Lot of subshells; this can be reduced to a straightforward conditional.

Use -q to silence grep matches + per grep manpages:

If no FILE is given [...] nonrecursive searches read standard input.

[kevinAlbs]

Thank you for the suggestion. Updated.