contrib: "set -e" behaves weird in subshells followed by OR. don't use.

This exits as expected:
```
$ cat s1.sh
#!/bin/bash
set -e
(
    echo "a"
    false
    echo "b"
)

$ ./s1.sh
a
```
This does NOT exit, seemingly because of the outer context?!
```
$ cat s2.sh
#!/bin/bash
set -e
(
    echo "a"
    false
    echo "b"
) || echo "c"

$ ./s2.sh
a
b
```

ref https://unix.stackexchange.com/questions/65532/why-does-set-e-not-work-inside-subshells-with-parenthesis-followed-by-an-or

contrib/osx/make_osx.sh

@@ -117,7 +117,7 @@ PYINSTALLER_COMMIT="306d4d92580fea7be7ff2c89ba112cdc6f73fac1"
     popd
     # sanity check bootloader is there:
     [[ -e "PyInstaller/bootloader/Darwin-64bit/runw" ]] || fail "Could not find runw in target dir!"
-) || fail "PyInstaller build failed"
+)
 info "Installing PyInstaller."
 python3 -m pip install --no-build-isolation --no-dependencies \
     --cache-dir "$PIP_CACHE_DIR" --no-warn-script-location "$CACHEDIR/pyinstaller"
@@ -144,7 +144,7 @@ info "preparing electrum-locale."
     "$CONTRIB/locale/build_cleanlocale.sh"
     # we want the binary to have only compiled (.mo) locale files; not source (.po) files
     rm -r "$PROJECT_ROOT/electrum/locale/locale"/*/electrum.po
-) || fail "failed generating locale"
+)
 
 
 if ls "$DLL_TARGET_DIR"/libsecp256k1.*.dylib 1> /dev/null 2>&1; then