Update Go (+deps) to modern version

[ChefAustin]

• Updated Go to 1.21
• Updated all dependencies
• Removes use of deprecated -i flag on go build (see: change 415094)
• Moved off incompatible version of shirou/gopsutil to a natively compatible one; resolves this warning:

iostat_darwin.c:28:2: warning: 'IOMasterPort' is deprecated: first deprecated in macOS 12.0 [-Wdeprecated-declarations]
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/IOKit.framework/Headers/IOKitLib.h:143:1: note: 'IOMasterPort' has been explicitly marked deprecated here

Tests pass:

$ make test
go test -cover -race -v github.com/airbnb/gosal/cmd/gosal github.com/airbnb/gosal/config github.com/airbnb/gosal/sal github.com/airbnb/gosal/version github.com/airbnb/gosal/xpreports github.com/airbnb/gosal/xpreports/cm github.com/airbnb/gosal/xpreports/linux github.com/airbnb/gosal/xpreports/windows
?   	github.com/airbnb/gosal/cmd/gosal	[no test files]
?   	github.com/airbnb/gosal/config	[no test files]
?   	github.com/airbnb/gosal/xpreports	[no test files]
?   	github.com/airbnb/gosal/xpreports/linux	[no test files]
?   	github.com/airbnb/gosal/xpreports/windows	[no test files]
=== RUN   TestCheckin
--- PASS: TestCheckin (0.00s)
PASS
coverage: 60.0% of statements
ok  	github.com/airbnb/gosal/sal	(cached)	coverage: 60.0% of statements
=== RUN   TestVersion
--- PASS: TestVersion (0.00s)
PASS
coverage: 6.2% of statements
ok  	github.com/airbnb/gosal/version	(cached)	coverage: 6.2% of statements
=== RUN   TestFlattenMapStringInterface
--- PASS: TestFlattenMapStringInterface (0.00s)
PASS
coverage: 45.8% of statements
ok  	github.com/airbnb/gosal/xpreports/cm	(cached)	coverage: 45.8% of statements