ldgen: override LC_ALL to C before running objdump
ldgen: override LC_ALL to C before running objdump

When using a Linux system configured with `zh_CN.UTF-8` as `$LANG`,
and running raw cmake command to build the project (rather than using
`idf.py build`), output of objdump will be Chinese
(like `在归档文件 libesp_pm.a 中`), resulting in parsing error
`pyparsing.ParseException: Expected "In archive" (at char 0), (line:1, col:1)`
at entity.py line 129.

This commit forces objdump to use raw locale setting (`C`), to ensure
it always make English output that's able to be parsed.

Closes https://github.com/espressif/esp-idf/pull/7903

espressif/esp-idf,espressif/esp-idf,espressif/esp-idf,espressif/esp-idf