[tailscale] runtime: add TailscaleNumTimers for metrics

Updates tailscale/go#141

[tailscale] net/http: add SetResponseWriteEnforcer

To use with Trackers, inject the Tracker into the Request context with
http.Server.BaseContext so that it is accessible in the
SetResponseWriteEnforcer callback. Close the injected Tracker in a defer at the
first layer of handle.

Updates tailscale/corp#7821
Updates #55

Go 1.25.3

Merge tag 'go1.25.3' of https://go.googlesource.com/go into bradfitz/1.25.3

Go 1.25.2

Merge tag 'go1.25.2' of https://go.googlesource.com/go into bradfitz/1.25.2

Updates tailscale/go#135

build-aa85d1541af0921f830f053f29d91971fa5838f6

Merge branch 'release-branch.go1.25' of https://go.googlesource.com/g…

go/types: relax NewSignatureType for append(slice, str...)

CL 688815 contained a partial fix for the reported bug, but NewSignatureType contined to panic. This change relaxes it to permit construction of the type "func([]byte, B) []byte" where "type B []byte". We must do so because a client may instantiate the type "func([]byte, T...)" where [T string|[]byte] at T=B, and may have no way to know that they are dealing with this very special edge case of append.

Added a regression test of NewSignatureType, which I should have done in the earlier CL.

Also, make typestring less pedantic and fragile.

Updates tailscale/corp#31755

Change-Id: I3d8f8609582149f9c9f8402a04ad516c2c63bbc6

.github/workflows: enable building of arm64 windows

We now have some engineers running ARM64 Windows VMs on their MacBooks.
We should start building a native toolchain for that use case.

Updates #47

Signed-off-by: Aaron Klotz <[email protected]>

net/http: fix data race in client

Updates golang/go#73522
Updates tailscale/go#131

Co-authored-by: Damien Neil <[email protected]>
Change-Id: I6fb408a0b03bc387f443e17e6f9d0bac32eff31e

Merge pull request #132 from tailscale/aaron/build_windows_arm64

.github/workflows: enable building of arm64 windows

net/http: fix data race in client

Updates golang/go#73522
Updates tailscale/go#131

Co-authored-by: Damien Neil <[email protected]>
Change-Id: I6fb408a0b03bc387f443e17e6f9d0bac32eff31e