gitignore not ignoring opencv2.framework

I am trying to make git ignore the opencv2.framework I have imported into my project. However, even though I am adding opencv2.framework into my .gitignore, every time I run git status on my terminal, all the opencv2.framework files are showing up as new files. Could anybody help? Thanks! This is what my .gitignore file looks like: (I wrote opencv2.framework under ##Various Settings)

# Xcode
#
# gitignore contributors: remember to update Global/Xcode.gitignore, Objective-C.gitignore & Swift.gitignore

## Build generated
build/
DerivedData/

## Various settings
*.pbxuser
!default.pbxuser
*.mode1v3
!default.mode1v3
*.mode2v3
!default.mode2v3
*.perspectivev3
!default.perspectivev3
xcuserdata/
opencv2.framework/

## Other
*.moved-aside
*.xccheckout
*.xcscmblueprint

## Obj-C/Swift specific
*.hmap
*.ipa
*.dSYM.zip
*.dSYM

## Playgrounds
timeline.xctimeline
playground.xcworkspace

# Swift Package Manager
#
# Add this line if you want to avoid checking in source code from Swift Package Manager dependencies.
# Packages/
# Package.pins
.build/

# CocoaPods
#
# We recommend against adding the Pods directory to your .gitignore. However
# you should judge for yourself, the pros and cons are mentioned at:
# https://guides.cocoapods.org/using/using-cocoapods.html#should-i-check-the-pods-directory-into-source-control
#
# Pods/

# Carthage
#
# Add this line if you want to avoid checking in source code from Carthage dependencies.
# Carthage/Checkouts

Carthage/Build

# fastlane
#
# It is recommended to not store the screenshots in the git repo. Instead, use fastlane to re-generate the
# screenshots whenever they are needed.
# For more information about the recommended setup visit:
# https://docs.fastlane.tools/best-practices/source-control/#source-control

fastlane/report.xml
fastlane/Preview.html
fastlane/screenshots
fastlane/test_output

Solution

Just in case, see if git status changes after:

cd /path/to/my/repo
git rm -r --cached opencv2.framework/

If it does (and you don't see anymore opencv2.framework/ files), commit your current state.

You need to execute the git rm -r --cached:

in the parent repo of the folder to remove (parent of opencv2.framework/).
Do add and commit (and eventually push), in order to record that deletion from the git repo (but not from the disk, thanks to the --cached option);
in order to delete those tracked files, as a .gitignore rule only applies to untracked files.