guix: Specify symbols in modules explicitly

This change improves the maintainability of the manifest:
(1) It allows to remove the module when the specified symbols are no
    longer used.
(2) It prevents accidental use of other symbols, such as `bash`
    instead of `bash-minimal`.

Author: hebasto

contrib/guix/manifest.scm

@@ -1,28 +1,28 @@
 (use-modules (gnu packages)
              (gnu packages autotools)
-             (gnu packages bash)
+             ((gnu packages bash) #:select (bash-minimal))
              (gnu packages bison)
-             (gnu packages certs)
-             (gnu packages cdrom)
-             (gnu packages cmake)
+             ((gnu packages certs) #:select (nss-certs))
+             ((gnu packages cdrom) #:select (xorriso))
+             ((gnu packages cmake) #:select (cmake-minimal))
              (gnu packages commencement)
              (gnu packages compression)
              (gnu packages cross-base)
              (gnu packages file)
              (gnu packages gawk)
              (gnu packages gcc)
-             (gnu packages installers)
-             (gnu packages linux)
+             ((gnu packages installers) #:select (nsis-x86_64))
+             ((gnu packages linux) #:select (linux-libre-headers-5.15 util-linux))
              (gnu packages llvm)
              (gnu packages mingw)
              (gnu packages moreutils)
              (gnu packages pkg-config)
-             (gnu packages python)
+             ((gnu packages python) #:select (python-minimal))
              ((gnu packages python-build) #:select (python-tomli))
-             (gnu packages python-crypto)
-             (gnu packages python-web)
-             (gnu packages tls)
-             (gnu packages version-control)
+             ((gnu packages python-crypto) #:select (python-asn1crypto))
+             ((gnu packages python-web) #:select (python-requests))
+             ((gnu packages tls) #:select (openssl))
+             ((gnu packages version-control) #:select (git-minimal))
              (guix build-system cmake)
              (guix build-system gnu)
              (guix build-system python)
@@ -31,7 +31,7 @@
              (guix git-download)
              ((guix licenses) #:prefix license:)
              (guix packages)
-             (guix utils))
+             ((guix utils) #:select (substitute-keyword-arguments)))
 
 (define-syntax-rule (search-our-patches file-name ...)
   "Return the list of absolute file names corresponding to each