[CI][Dev] Fix shellcheck errors in cpp/thirdparty/download_dependencies.sh

[hiroyuki-sato]

Describe the enhancement requested

This is the sub issue #44748.

• SC2086: Double quote to prevent globbing and word splitting.

shellcheck cpp/thirdparty/download_dependencies.sh

In cpp/thirdparty/download_dependencies.sh line 49:
  source ${SOURCE_DIR}/versions.txt
         ^-----------^ SC2086 (info): Double quote to prevent globbing and word splitting.

Did you mean:
  source "${SOURCE_DIR}"/versions.txt

For more information:
  https://www.shellcheck.net/wiki/SC2086 -- Double quote to prevent globbing ...

Component(s)

Continuous Integration,Developer Tools

[raulcd]

Issue resolved by pull request 51284
#51284