Remove some duplicated words (#6882)

Signed-off-by: Pham Duc Hanh <hanhpd@fujitsu.com>

promql/parser/parse.go

@@ -220,7 +220,7 @@ func ParseSeriesDesc(input string) (labels labels.Labels, values []SequenceValue
 	return labels, values, err
 }
 
-// addParseErrf formats the error and and appends it to the list of parsing errors.
+// addParseErrf formats the error and appends it to the list of parsing errors.
 func (p *parser) addParseErrf(positionRange PositionRange, format string, args ...interface{}) {
 	p.addParseErr(positionRange, errors.Errorf(format, args...))
 }

web/ui/react-app/README.md

@@ -4,7 +4,7 @@ This file explains how to work with the React-based Prometheus UI.
 
 ## Introduction
 
-The [React-based](https://reactjs.org/) Prometheus UI was was bootstrapped using [Create React App](https://github.com/facebook/create-react-app), a popular toolkit for generating React application setups. You can find general information about Create React App on [their documentation site](https://create-react-app.dev/).
+The [React-based](https://reactjs.org/) Prometheus UI was bootstrapped using [Create React App](https://github.com/facebook/create-react-app), a popular toolkit for generating React application setups. You can find general information about Create React App on [their documentation site](https://create-react-app.dev/).
 
 Instead of plain JavaScript, we use [TypeScript](https://www.typescriptlang.org/) to ensure typed code.