fix: don't use defer in a loop

[ghost]

These changes fixes a crash in tests when using WithCompleteRequest() or WithCompleteResponse()` with multiple headers.

unexpected fault address 0x1d4c860
fatal error: fault
[signal SIGSEGV: segmentation violation code=0x2 addr=0x1d4c860 pc=0x4a28fd]

goroutine 14 gp=0xc0003c28c0 m=3 mp=0xc00009d008 [running]:
runtime.throw({0x1e99d7e?, 0xc000111f80?})
	GOROOT/src/runtime/panic.go:1023 +0x5c fp=0xc0000eb660 sp=0xc0000eb630 pc=0x46cd7c
runtime.sigpanic()
	GOROOT/src/runtime/signal_unix.go:895 +0x285 fp=0xc0000eb6c0 sp=0xc0000eb660 pc=0x487265
runtime/internal/atomic.casPointer(0x1d4c860?, 0x46c765?, 0x46b700?)
	GOROOT/src/runtime/atomic_pointer.go:63 +0x3d fp=0xc0000eb6e0 sp=0xc0000eb6c0 pc=0x4a28fd
runtime/internal/atomic.(*UnsafePointer).CompareAndSwap(...)
	GOROOT/src/runtime/internal/atomic/types.go:512
runtime/internal/atomic.(*Pointer[...]).CompareAndSwap(...)
	GOROOT/src/runtime/internal/atomic/types.go:570
runtime.deferconvert(0xc0000edc88)
	GOROOT/src/runtime/panic.go:436 +0x77 fp=0xc0000eb720 sp=0xc0000eb6e0 pc=0x46b777
runtime.(*_panic).nextDefer(0xc0000eb768)
	GOROOT/src/runtime/panic.go:879 +0x125 fp=0xc0000eb750 sp=0xc0000eb720 pc=0x46c765
runtime.deferreturn()
	GOROOT/src/runtime/panic.go:598 +0x68 fp=0xc0000eb7e0 sp=0xc0000eb750 pc=0x46be08
github.com/pact-foundation/pact-go/v2/internal/native.(*Interaction).withHeaders(0xc00043034c, 0x0, 0xc0000ebc60)
	github.com/pact-foundation/pact-go/v2/internal/native/mock_server.go:709 +0x1ec fp=0xc0000eb8d0 sp=0xc0000eb7e0 pc=0xf6d60c
github.com/pact-foundation/pact-go/v2/internal/native.(*Interaction).WithRequestHeaders(...)
	github.com/pact-foundation/pact-go/v2/internal/native/mock_server.go:686
github.com/pact-foundation/pact-go/v2/consumer.(*Interaction).WithCompleteRequest(0xc00011e198, {{0x1e98bce, 0x3}, {0x20178c8, 0x2010de0}, 0x0, 0xc0004441e0, {0x0, 0x0}})
	github.com/pact-foundation/pact-go/v2/consumer/interaction.go:31 +0x3ec fp=0xc0000ebd00 sp=0xc0000eb8d0 pc=0xf7678c
github.com/pact-foundation/pact-go/v2/consumer.(*V4UnconfiguredInteraction).WithCompleteRequest(...)
	github.com/pact-foundation/pact-go/v2/consumer/http_v4.go:97

[coveralls]

coverage: 29.383% (+0.03%) from 29.358%
when pulling ac7f9cf on lbcjbb:fix-crash
into a396cac on pact-foundation:master.

[mefellows]

Thanks for this, i'll get a new release out shortly.