Intermittent unit test: `TestRequestWithBodyReplyEndToEndWithTLS`

I have seen the unit test `TestRequestWithBodyReplyEndToEndWithTLS` intermittently fail in GitHub actions. For example: https://github.com/hyperledger/firefly/actions/runs/7035574807/job/19146264505?pr=1427

```
=== RUN TestRequestWithBodyReplyEndToEndWithTLS
time="2023-11-29T16:32:40Z" level=error msg="Failed to invoke webhook: Put \"https://127.0.0.1:8443/myapi/my/sub/path%3Fescape_query?dynamic-query=dynamicqueryval&my-query=myqueryval\": dial tcp 127.0.0.1:8443: connect: connection refused" webhook=
webhooks_test.go:577:
Error Trace: /home/runner/work/firefly/firefly/internal/events/webhooks/webhooks_test.go:577
/home/runner/work/firefly/firefly/internal/events/webhooks/value.go:584
/home/runner/work/firefly/firefly/internal/events/webhooks/value.go:368
/home/runner/work/firefly/firefly/internal/events/webhooks/callbacks.go:24
/home/runner/work/firefly/firefly/internal/events/webhooks/webhooks.go:470
/home/runner/work/firefly/firefly/internal/events/webhooks/webhooks.go:539
/home/runner/work/firefly/firefly/internal/events/webhooks/webhooks_test.go:584
Error: Not equal:
expected: "batch_pin"
actual : ""

Diff:
--- Expected
+++ Actual
@@ -1,2 +1,2 @@
-(fftypes.FFEnum) (len=9) "batch_pin"
+(fftypes.FFEnum) ""

Test: TestRequestWithBodyReplyEndToEndWithTLS
webhooks_test.go:578:
Error Trace: /home/runner/work/firefly/firefly/internal/events/webhooks/webhooks_test.go:578
/home/runner/work/firefly/firefly/internal/events/webhooks/value.go:584
/home/runner/work/firefly/firefly/internal/events/webhooks/value.go:368
/home/runner/work/firefly/firefly/internal/events/webhooks/callbacks.go:24
/home/runner/work/firefly/firefly/internal/events/webhooks/webhooks.go:470
/home/runner/work/firefly/firefly/internal/events/webhooks/webhooks.go:539
/home/runner/work/firefly/firefly/internal/events/webhooks/webhooks_test.go:584
Error: Not equal:
expected: "myheaderval2"
actual : ""

Diff:
--- Expected
+++ Actual
@@ -1 +1 @@
-myheaderval2
+
Test: TestRequestWithBodyReplyEndToEndWithTLS
webhooks_test.go:579:
Error Trace: /home/runner/work/firefly/firefly/internal/events/webhooks/webhooks_test.go:579
/home/runner/work/firefly/firefly/internal/events/webhooks/value.go:584
/home/runner/work/firefly/firefly/internal/events/webhooks/value.go:368
/home/runner/work/firefly/firefly/internal/events/webhooks/callbacks.go:24
/home/runner/work/firefly/firefly/internal/events/webhooks/webhooks.go:470
/home/runner/work/firefly/firefly/internal/events/webhooks/webhooks.go:539
/home/runner/work/firefly/firefly/internal/events/webhooks/webhooks_test.go:584
Error: Not equal:
expected: "replyvalue"
actual : ""

Diff:
--- Expected
+++ Actual
@@ -1 +1 @@
-replyvalue
+
Test: TestRequestWithBodyReplyEndToEndWithTLS
webhooks_test.go:580:
Error Trace: /home/runner/work/firefly/firefly/internal/events/webhooks/webhooks_test.go:580
/home/runner/work/firefly/firefly/internal/events/webhooks/value.go:584
/home/runner/work/firefly/firefly/internal/events/webhooks/value.go:368
/home/runner/work/firefly/firefly/internal/events/webhooks/callbacks.go:24
/home/runner/work/firefly/firefly/internal/events/webhooks/webhooks.go:470
/home/runner/work/firefly/firefly/internal/events/webhooks/webhooks.go:539
/home/runner/work/firefly/firefly/internal/events/webhooks/webhooks_test.go:584
Error: Not equal:
expected: 200
actual : 502
Test: TestRequestWithBodyReplyEndToEndWithTLS
webhooks_test.go:587: PASS: RegisterConnection(string,string)
webhooks_test.go:577:
Error Trace: /home/runner/work/firefly/firefly/internal/events/webhooks/webhooks_test.go:577
/home/runner/work/firefly/firefly/internal/events/webhooks/value.go:584
/home/runner/work/firefly/firefly/internal/events/webhooks/value.go:368
/home/runner/work/firefly/firefly/internal/events/webhooks/webhooks_test.go:587
Error: Not equal:
expected: "batch_pin"
actual : ""

Diff:
--- Expected
+++ Actual
@@ -1,2 +1,2 @@
-(fftypes.FFEnum) (len=9) "batch_pin"
+(fftypes.FFEnum) ""

Test: TestRequestWithBodyReplyEndToEndWithTLS
webhooks_test.go:578:
Error Trace: /home/runner/work/firefly/firefly/internal/events/webhooks/webhooks_test.go:578
/home/runner/work/firefly/firefly/internal/events/webhooks/value.go:584
/home/runner/work/firefly/firefly/internal/events/webhooks/value.go:368
/home/runner/work/firefly/firefly/internal/events/webhooks/webhooks_test.go:587
Error: Not equal:
expected: "myheaderval2"
actual : ""

Diff:
--- Expected
+++ Actual
@@ -1 +1 @@
-myheaderval2
+
Test: TestRequestWithBodyReplyEndToEndWithTLS
webhooks_test.go:579:
Error Trace: /home/runner/work/firefly/firefly/internal/events/webhooks/webhooks_test.go:579
/home/runner/work/firefly/firefly/internal/events/webhooks/value.go:584
/home/runner/work/firefly/firefly/internal/events/webhooks/value.go:368
/home/runner/work/firefly/firefly/internal/events/webhooks/webhooks_test.go:587
Error: Not equal:
expected: "replyvalue"
actual : ""

Diff:
--- Expected
+++ Actual
@@ -1 +1 @@
-replyvalue
+
Test: TestRequestWithBodyReplyEndToEndWithTLS
webhooks_test.go:580:
Error Trace: /home/runner/work/firefly/firefly/internal/events/webhooks/webhooks_test.go:580
/home/runner/work/firefly/firefly/internal/events/webhooks/value.go:584
/home/runner/work/firefly/firefly/internal/events/webhooks/value.go:368
/home/runner/work/firefly/firefly/internal/events/webhooks/webhooks_test.go:587
Error: Not equal:
expected: 200
actual : 502
Test: TestRequestWithBodyReplyEndToEndWithTLS
webhooks_test.go:587: PASS: DeliveryResponse(string,mock.argumentMatcher)
--- FAIL: TestRequestWithBodyReplyEndToEndWithTLS (0.35s)
```

[logs_8540.zip](https://github.com/hyperledger/firefly/files/13503270/logs_8540.zip)