Fix pkgconfig dependencies (#40524)

`pkgconfig` is the correct virtual dependency.

var/spack/repos/builtin/packages/apr-util/package.py

@@ -32,7 +32,7 @@ class AprUtil(AutotoolsPackage):
     depends_on("postgresql", when="+pgsql")
     depends_on("sqlite", when="+sqlite")
     depends_on("unixodbc", when="+odbc")
-    depends_on("pkg-config", type="build", when="+crypto ^openssl~shared")
+    depends_on("pkgconfig", type="build", when="+crypto ^openssl~shared")
 
     @property
     def libs(self):

var/spack/repos/builtin/packages/libpostal/package.py

@@ -28,7 +28,7 @@ class Libpostal(AutotoolsPackage):
     depends_on("libtool", type="build")
     depends_on("m4", type="build")
     depends_on("curl", type="build")
-    depends_on("pkg-config", type="build")
+    depends_on("pkgconfig", type="build")
 
     def autoreconf(self, spec, prefix):
         which("sh")("bootstrap.sh")