Use -fno-common in CI workflow builds

[jphickey]

Checklist (Please check before submitting)

• I reviewed the Contributing Guide.
• I reviewed the cFS README.md file to see if the feature is in the major future work.
• I performed a cursory search to see if the feature request is relevant, not redundant, nor in conflict with other tickets.

Is your feature request related to a problem? Please describe.
Some versions of the GNU toolchains enable -fcommon by default, so globals end up in a "common" section rather than the normal "bss" section. The CFS apps should not rely on common sections, as it can mask duplicate symbols and cause strange results if not expected. In particular, this feature hid linking errors in nasa/LC#51.

Describe the solution you'd like
Add -fno-common to the default arch_build_custom_native.cmake file so this feature is consistently not enabled rather than assuming the default for whatever version of gcc/binutils is being used at the time.

Requester Info
Joseph Hickey, Vantage Systems, Inc.

[jphickey]

For now just asking the question, trivial PR can be submitted if we decide to do this.

[jphickey]

I realized this change needs to happen in CFE, as this is where the reference copy of arch_build_custom.cmake lives.