fix: export interfaces in typegen

[DefiCake]

• Closes Typegen does not export interfaces #2842

Summary

Just prefixing the hbs file with the export keyword.

Checklist

• I added — tests to prove my changes
• I updated — all the necessary docs
• I reviewed — the entire PR myself, using the GitHub UI
• I described — all breaking changes and the Migration Guide

[arboleya]

Good catch! Thanks for the help @DefiCake. 🙏

[github-actions]

Coverage Report:

Lines	Branches	Functions	Statements
79.35%(-0.01%)	71.47%(-0.18%)	77.32%(+0.02%)	79.48%(-0.01%)

Changed Files:

Ok	File (✨=New File)	Lines	Branches	Functions	Statements
🔴	packages/account/src/account.ts	82.31% (+1.16%)	65.07% (+1.14%)	82.35% (+0.54%)	82% (+1.15%)
🔴	packages/account/src/providers/provider.ts	67.31% (-1.53%)	62.28% (-1.54%)	73.49% (-0.31%)	67.3% (-1.49%)
🔴	packages/account/src/test-utils/launchNode.ts	98.27% (+0.01%)	85.24% (+0.5%)	100% (+0%)	98.36% (+0.02%)
🔴	packages/contract/src/contract-factory.ts	58.33% (-0.29%)	46.42% (+0.27%)	54.54% (+0%)	58.33% (-0.29%)
🔴	packages/contract/src/util.ts	93.75% (+0.42%)	0% (+0%)	66.66% (+0%)	88.88% (+0.65%)
🔴	packages/create-fuels/src/cli.ts	85.5% (+0.21%)	37.5% (-2.5%)	100% (+0%)	85.5% (+0.21%)