[v8] Fix Windows build relocation error

[anujc25]

Description of the Change

Generate architecture-specific rsrc syso files with explicit -arch flags to prevent GOARCH linking conflicts where an amd64 syso file gets linked into a 386 executable.

Before the change:

❯ make out/cf-cli_win32.exe
make out/cf-cli_winx64.exe
rsrc -ico cf.ico -o rsrc.syso
GOARCH=386 GOOS=windows go build -tags="forceposix" -o out/cf-cli_win32.exe -ldflags "-w -s -X code.cloudfoundry.org/cli/v8/version.binarySHA=$(git rev-parse --short HEAD) -X code.cloudfoundry.org/cli/v8/version.binaryBuildDate=$(date -u +"%Y-%m-%d") -X code.cloudfoundry.org/cli/v8/version.binaryVersion=$(git describe --tags --abbrev=0)" .
# code.cloudfoundry.org/cli/v8
$WORK/b001/_pkg_.a(rsrc.syso): 814043: unknown relocation type 3
make: *** [out/cf-cli_win32.exe] Error 1
GOARCH=amd64 GOOS=windows go build -tags="forceposix" -o out/cf-cli_winx64.exe -ldflags "-w -s -X code.cloudfoundry.org/cli/v8/version.binarySHA=$(git rev-parse --short HEAD) -X code.cloudfoundry.org/cli/v8/version.binaryBuildDate=$(date -u +"%Y-%m-%d") -X code.cloudfoundry.org/cli/v8/version.binaryVersion=$(git describe --tags --abbrev=0)" .
rm rsrc.syso

After the change:

❯ make out/cf-cli_win32.exe
make out/cf-cli_winx64.exe
rsrc -arch 386 -ico cf.ico -o rsrc_windows_386.syso
GOARCH=386 GOOS=windows go build -tags="forceposix" -o out/cf-cli_win32.exe -ldflags "-w -s -X code.cloudfoundry.org/cli/v8/version.binarySHA=$(git rev-parse --short HEAD) -X code.cloudfoundry.org/cli/v8/version.binaryBuildDate=$(date -u +"%Y-%m-%d") -X code.cloudfoundry.org/cli/v8/version.binaryVersion=$(git describe --tags --abbrev=0)" .
rm rsrc_windows_386.syso
rsrc -arch amd64 -ico cf.ico -o rsrc_windows_amd64.syso
GOARCH=amd64 GOOS=windows go build -tags="forceposix" -o out/cf-cli_winx64.exe -ldflags "-w -s -X code.cloudfoundry.org/cli/v8/version.binarySHA=$(git rev-parse --short HEAD) -X code.cloudfoundry.org/cli/v8/version.binaryBuildDate=$(date -u +"%Y-%m-%d") -X code.cloudfoundry.org/cli/v8/version.binaryVersion=$(git describe --tags --abbrev=0)" .
rm rsrc_windows_amd64.syso

Why Is This PR Valuable?

Unblocks the release.

Applicable Issues

How Urgent Is The Change?

time-sensitive to unblock the release.

Other Relevant Parties

[vuil]

lgtm, thanks!

[prkalle]

LGTM. Thanks!