Unwrap processing exception from REST Client when returning a Uni #38455

Job	Run time
CI Sanity Check	31s
Attach pull request number	2s
Initial JDK 17 Build	13m 54s
Calculate Test Jobs	8s
JVM Tests - JDK 17	41m 18s
JVM Tests - JDK 21	41m 58s
Maven Tests - JDK ${{ matrix.java.name }}	0s
Devtools Tests - JDK ${{ matrix.java.name }}	0s
JVM Tests - JDK 17 Windows	42m 55s
Kubernetes Tests - JDK ${{ matrix.java.name }}	0s
Gradle Tests - JDK ${{ matrix.java.name }}	0s
Native Tests - Main	1m 49s
Quickstarts Compilation - JDK 17	5m 26s
MicroProfile TCKs Tests	10m 23s
Native Tests - Data3	5m 27s
Native Tests - Data4	7m 3s
Native Tests - Messaging1	21m 40s
Native Tests - Virtual Thread - Main	3m 38s
Native Tests - Security2	9m 3s
Native Tests - Virtual Thread - Messaging	10m 5s
Native Tests - Security3	5m 18s
Native Tests - Cache	7m 35s
Native Tests - HTTP	22m 40s
Native Tests - Misc1	6m 17s
Native Tests - Misc3	6m 15s
Native Tests - Misc4	9m 2s
Native Tests - gRPC	5m 35s
Build report	18s
	4h 38m 20s

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