Remove ppc64le and s390x support from npb-is image

The npb-is image was failing to build on ppc64le with relocation overflow:
  relocation truncated to fit: R_PPC64_TOC16_HA against symbol 'key_array'

Remove ppc64le and s390x from supported architectures:
- The IS benchmark with CLASS=D has ~8GB data arrays that require special
  compiler flags for non-x86 architectures
- ppc64le and s390x builds are difficult to test and maintain
- Keep amd64 and arm64 which are the primary node performance test targets

I don't think these arch(es) ever worked!

Signed-off-by: Davanum Srinivas <davanum@gmail.com>

test/images/node-perf/npb-is/BASEIMAGE

@@ -1,4 +1,2 @@
 linux/amd64=debian:bookworm-slim
 linux/arm64=arm64v8/debian:bookworm-slim
-linux/ppc64le=ppc64le/debian:bookworm-slim
-linux/s390x=s390x/debian:bookworm-slim

test/images/node-perf/npb-is/Dockerfile

@@ -31,13 +31,11 @@ RUN sed -i '1i#!/bin/sh' sys/print_header sys/print_instructions
 
 # Create build config based on the architecture and build the workload.
 # arm64 requires special flags to avoid relocation overflow with large binaries:
-#   -mcmodel=large: use large code model for > 4GB address space
+#   -mcmodel=large: use large code model for address space beyond default limits
 #   -fno-PIE: disable position-independent executable (incompatible with large model)
 #   -mno-outline-atomics: inline atomics to avoid linker issues
 RUN if [ $(arch) = "aarch64" ]; then \
     sed 's/-mcmodel=medium/-mcmodel=large -fno-PIE -mno-outline-atomics/g' config/NAS.samples/make.def.gcc_x86 > config/make.def; \
-elif [ $(arch) != "x86_64" ]; then \
-    sed s/-mcmodel=medium//g config/NAS.samples/make.def.gcc_x86 > config/make.def; \
 else \
     cp config/NAS.samples/make.def.gcc_x86 config/make.def; \
 fi

test/images/node-perf/npb-is/VERSION

@@ -1 +1 @@
-1.6.0
+1.7.0