Rollup merge of #61603 - Goirad:increase-sgx-heapsize, r=alexcrichton

Increases heap size available during testing for SGX

PR [61540](#61540) causes at least one test to fail when run for the SGX platform due to lack of memory. This PR increases the heapsize available during tests, which is a good thing regardless of the status of that PR.

Author: Centril

src/libstd/Cargo.toml

@@ -87,3 +87,5 @@ std_detect_dlsym_getauxval = []
 [package.metadata.fortanix-sgx]
 # Maximum possible number of threads when testing
 threads = 125
+# Maximum heap size
+heap_size = 0x8000000