ARM64 supported container image building for Tentacle

[2good4hisowngood]

In reference to issue #7464 I am opening this issue to try offering a Pull Request to give ARM64 Build support using the buildx tool provided by Docker.

[2good4hisowngood]

I had hoped to PR add in the buildx tooling to what I thought was your docker image build step, but it looks like you're calling a dotnet build here:

OctopusTentacle/build.sh

Line 61 in 32b3db3

"$DOTNET_EXE" build "$BUILD_PROJECT_FILE" /nodeReuse:false /p:UseSharedCompilation=false -nologo -clp:NoSummary --verbosity quiet

It appears that your builds may be done on a teamcity or OD server, based on this readme.

I had planned to try adding something like this for your build queue to output the ARM64 image:

docker buildx build --pull --platform linux/amd64,linux/arm64 --push .

[powareverb]

Especially keen to see this, to allow for AWS Graviton support.

[vaujo6y]

Also keen to see this, as would love to move tentacles onto AWS Graviton.