Merge #21321: guix: Add curl to required tool list

97f1062 guix: Add curl to required tool list (Hennadii Stepanov)

Pull request description:

  On Ubuntu Hirsute (minimum installation) with the system `guix` package:
  ```
  $ HOSTS=x86_64-linux-gnu ./contrib/guix/guix-build.sh
  make: Entering directory '/home/hebasto/bitcoin/depends'
  make[1]: Entering directory '/home/hebasto/bitcoin/depends'
  Checksum missing or mismatched for boost source. Forcing re-download.
  Fetching boost_1_71_0.tar.bz2 from https://dl.bintray.com/boostorg/release/1.71.0/source/
  /bin/sh: 1: curl: not found
  Fetching boost_1_71_0.tar.bz2 from https://bitcoincore.org/depends-sources
  /bin/sh: 1: curl: not found
  make[1]: *** [funcs.mk:276: /home/hebasto/bitcoin/depends/sources/download-stamps/.stamp_fetched-boost-boost_1_71_0.tar.bz2.hash] Error 127
  make[1]: Leaving directory '/home/hebasto/bitcoin/depends'
  make: *** [Makefile:281: download-linux] Error 2
  make: Leaving directory '/home/hebasto/bitcoin/depends'
  ```

  This PR fixes that issue.

ACKs for top commit:
  laanwj:
    ACK 97f1062
  jonasschnelli:
    utACK 97f1062

Tree-SHA512: b9e1ba966782b13e25c85d4a9cfd381bcda190244cb9821ae1a72fd51f82f23ed5e98d9a02384619e3299feb7a34e1da8b9190081a6005221f47f93ae18f3c0b

Author: laanwj

contrib/guix/guix-build.sh

@@ -9,7 +9,7 @@ set -e -o pipefail
 ################
 # Check 1: Make sure that we can invoke required tools
 ################
-for cmd in git make guix cat mkdir; do
+for cmd in git make guix cat mkdir curl; do
     if ! command -v "$cmd" > /dev/null 2>&1; then
         echo "ERR: This script requires that '$cmd' is installed and available in your \$PATH"
         exit 1