fix code parser for `:=` operator #1011

Job	Run time
Version Bump 🤜🤛	0s
Audit Dependencies 🕵️‍♂️ / oysteR scan 🦪	1m 33s
Coverage 📔 / Coverage 📔	2m 13s
Coverage 📔 / Covtracer 🐄	0s
gitleaks 💧 / gitleaks 💧	6s
Grammar Check 🔤 / Check 📝	7s
gitleaks 💧 / PII Check 💳	0s
License Check 🃏 / Check 🚩	34s
Check URLs 🌐 / Validate Links 🔎	0s
SuperLinter 🦸‍♀️ / SuperLinter 🦸‍♂️	1m 20s
Check URLs 🌐 / URL Checker 🔎	38s
SuperLinter 🦸‍♀️ / Lint R code 🧶	1m 27s
R CMD Check 🧬 / ghcr.io/insightsengineering/rstudio, version latest	2m 36s
R CMD Check (non-CRAN) 🧬 / ghcr.io/insightsengineering/rstudio, version latest	2m 31s
Roxygen 🅾 / Manual pages check 🏁	1m 42s
Spell Check 🆎 / Check spelling 🔠	1m 26s
Style Check 👗 / Check code style 🔠	1m 38s
Version Check 🏁 / Emoji in NEWS.md 📰	9s
Version Check 🏁 / Version check 🏁	3s
Coverage 📔 / Publish coverage report 📰	0s
R CMD Check (non-CRAN) 🧬 / Upload build tar.gz	0s
R CMD Check (non-CRAN) 🧬 / Publish JUnit HTML report 📰	0s
R CMD Check 🧬 / Upload build tar.gz	0s
R CMD Check 🧬 / Publish JUnit HTML report 📰	0s
	18m 3s

Provide feedback