actions: disable use-keyboxd

If the default home directory ~/.gnupg does not exist, GnuPG creates
this directory and a common.conf file with "use-keyboxd". If the option
use-keyboxd is enabled in common.conf, no keyrings are used at all and
keys are all maintained by the keyboxd process in its own database. This
seemingly includes any keyring specified via the --keyring option and
this breaks our signature verification of dependencies that we download
in our Windows pipelines.

windows/build.ps1

@@ -98,6 +98,13 @@ New-Item -Type Directory "${STAGE}\${LIBRESSL}" -Force
 New-Item -Type Directory "${STAGE}\${LIBCBOR}" -Force
 New-Item -Type Directory "${STAGE}\${ZLIB}" -Force
 
+# Create GNUPGHOME with an empty common.conf to disable use-keyboxd.
+# Recent default is to enable keyboxd which in turn ignores --keyring
+# arguments.
+$GpgHome = "${BUILD}\.gnupg"
+New-Item -Type Directory "${GpgHome}" -Force
+New-Item -Type File "${GpgHome}/common.conf" -Force
+
 # Create output directories.
 New-Item -Type Directory "${OUTPUT}" -Force
 New-Item -Type Directory "${OUTPUT}\${Arch}" -Force
@@ -117,8 +124,9 @@ try {
 		}
 
 		Copy-Item "$PSScriptRoot\libressl.gpg" -Destination "${BUILD}"
-		& $GPG --list-keys
-		& $GPG --quiet --no-default-keyring --keyring ./libressl.gpg `
+		& $GPG --homedir ${GpgHome} --list-keys
+		& $GPG --homedir ${GpgHome} --quiet --no-default-keyring `
+		    --keyring ./libressl.gpg `
 		    --verify .\${LIBRESSL}.tar.gz.asc .\${LIBRESSL}.tar.gz
 		if ($LastExitCode -ne 0) {
 			throw "GPG signature verification failed"

windows/cygwin.ps1

@@ -38,6 +38,13 @@ Write-Host "GPG: $GPG"
 New-Item -Type Directory "${Cygwin}" -Force
 New-Item -Type Directory "${Root}" -Force
 
+# Create GNUPGHOME with an empty common.conf to disable use-keyboxd.
+# Recent default is to enable keyboxd which in turn ignores --keyring
+# arguments.
+$GpgHome = "${Cygwin}\.gnupg"
+New-Item -Type Directory "${GpgHome}" -Force
+New-Item -Type File "${GpgHome}/common.conf" -Force
+
 # Fetch and verify Cygwin.
 try {
 	if (-Not (Test-Path ${Cygwin}\${Setup} -PathType leaf)) {
@@ -48,8 +55,8 @@ try {
 		Invoke-WebRequest ${URL}/${Setup}.sig `
 		    -OutFile ${Cygwin}\${Setup}.sig
 	}
-	& $GPG --list-keys
-	& $GPG --quiet --no-default-keyring `
+	& $GPG --homedir ${GpgHome} --list-keys
+	& $GPG --homedir ${GpgHome} --quiet --no-default-keyring `
 	    --keyring ${PSScriptRoot}/cygwin.gpg `
 	    --verify ${Cygwin}\${Setup}.sig ${Cygwin}\${Setup}
 	if ($LastExitCode -ne 0) {