fix: bash completion script

[Foo-x]

What does this PR do?

#6037

Fixed the bash completion script to complete scripts in package.json.

• local scripts="${matched%%\}*}"; didn't work if scripts contained } characters.
• Since re_comp_word_script was not defined, the condition ( "${COMPREPLY[*]}" =~ ${re_comp_word_script} ) was always true and completions for scripts were removed.

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• Documentation or TypeScript types (it's okay to leave the rest blank in this case)
• Code changes

How did you verify your code works?

package.json

before	after