build: update build targets (OS/ARCH)

[missinglink]

this PR makes some changes to the way the prebuilt binaries in ./build are generated:

• adds a new build target pbf2json.darwin-arm64 to support the new Macs
• deprecate and remove pbf2json.linux-arm (this was a 32-bit build)
• add pbf2json.linux-arm64 to replace it (64-bit linux ARM build)
• fix pbf2json.win32-x64 (this was a 32-bit build incorrectly labeled as 64-bit)

I'm assuming that both linux/darwin 64-bit ARM machines return arm64 as their arch and not arm?
Can someone with one of these machines please confirm with require('os') os.platform(), os.arch()?

note: this effectively drops support for 32-bit architectures, which I'm fine with, it is 2021 after all...

[missinglink]

The windows binary is named pbf2json.win32-x64, does that even make sense? ie. don't win32 and x64 contradict each other?

[edit] agh yeah this seems to be correct, weird, but correct:
https://nodejs.org/api/process.html#process_process_platform

[orangejulius]

Here you go :)

$ node
Welcome to Node.js v17.0.1.
Type ".help" for more information.
> const os = require('os');
undefined
> os.platform()
'darwin'
> os.arch()
'arm64'

[orangejulius]

I checked out this branch on my M1 Macbook Air. All the nodejs tests pass, and running go build works fine.

There's one tiny minor failure when running go test:

$ go test
--- FAIL: TestComputeCentroidForClosedPolygon (0.00s)
    centroid_test.go:84: 
        	Error Trace:	centroid_test.go:84
        	Error:      	Not equal: 
        	            	expected: "0.0000000"
        	            	actual  : "-0.0000000"
        	            	
        	            	Diff:
        	            	--- Expected
        	            	+++ Actual
        	            	@@ -1 +1 @@
        	            	-0.0000000
        	            	+-0.0000000
        	Test:       	TestComputeCentroidForClosedPolygon
FAIL
exit status 1
FAIL	github.com/pelias/pbf2json	0.123s