React deploy error on netlify?

```1:05:19 PM: Netlify Build                                                 
1:05:19 PM: ────────────────────────────────────────────────────────────────
1:05:19 PM: ​
1:05:19 PM: ❯ Version
1:05:19 PM:   @netlify/build 29.26.2
1:05:19 PM: ​
1:05:19 PM: ❯ Flags
1:05:19 PM:   baseRelDir: true
1:05:19 PM:   buildId: 654ddd1dbea46941453a55df
1:05:19 PM:   deployId: 654ddd1dbea46941453a55e1
1:05:19 PM: ​
1:05:19 PM: ❯ Current directory
1:05:19 PM:   /opt/build/repo
1:05:19 PM: ​
1:05:19 PM: ❯ Config file
1:05:19 PM:   No config file was defined: using default values.
1:05:19 PM: ​
1:05:19 PM: ❯ Context
1:05:19 PM:   production
1:05:19 PM: ​
1:05:19 PM: Build command from Netlify app                                
1:05:19 PM: ────────────────────────────────────────────────────────────────
1:05:19 PM: ​
1:05:19 PM: $ npm run build
1:05:19 PM: > [email protected] build
1:05:19 PM: > react-scripts build
1:05:20 PM: Creating an optimized production build...
1:05:23 PM: One of your dependencies, babel-preset-react-app, is importing the
1:05:23 PM: "@babel/plugin-proposal-private-property-in-object" package without
1:05:23 PM: declaring it in its dependencies. This is currently working because
1:05:23 PM: "@babel/plugin-proposal-private-property-in-object" is already in your
1:05:23 PM: node_modules folder for unrelated reasons, but it may break at any time.
1:05:23 PM: babel-preset-react-app is part of the create-react-app project, which
1:05:23 PM: is not maintianed anymore. It is thus unlikely that this bug will
1:05:23 PM: ever be fixed. Add "@babel/plugin-proposal-private-property-in-object" to
1:05:23 PM: your devDependencies to work around this error. This will make this message
1:05:23 PM: go away.
1:05:24 PM: 
1:05:24 PM: Treating warnings as errors because process.env.CI = true.
1:05:24 PM: Most CI servers set it automatically.
1:05:24 PM: 
1:05:24 PM: Failed to compile.
1:05:24 PM: 
1:05:24 PM: [eslint]
1:05:24 PM: src/components/Sidebar.js
1:05:24 PM:   Line 24:11:  The href attribute requires a valid value to be accessible. Provide a valid, navigable address as the href value. If you cannot provide a valid href, but still need the element to resemble a link, use a button and change it with appropriate styles. Learn more: https://github.com/jsx-eslint/eslint-plugin-jsx-a11y/blob/HEAD/docs/rules/anchor-is-valid.md  jsx-a11y/anchor-is-valid
1:05:24 PM: ​
1:05:24 PM: "build.command" failed                                        
1:05:24 PM: ────────────────────────────────────────────────────────────────
1:05:24 PM: ​
1:05:24 PM:   Error message
1:05:24 PM:   Command failed with exit code 1: npm run build (https://ntl.fyi/exit-code-1)
1:05:24 PM: ​
1:05:24 PM:   Error location
1:05:24 PM:   In Build command from Netlify app:
1:05:24 PM:   npm run build
1:05:24 PM: ​
1:05:24 PM:   Resolved config
1:05:24 PM:   build:
1:05:24 PM:     base: /opt/build/repo
1:05:24 PM:     command: npm run build
1:05:24 PM:     commandOrigin: ui
1:05:24 PM:     publish: /opt/build/repo/build
1:05:24 PM:     publishOrigin: ui
1:05:25 PM: Build failed due to a user error: Build script returned non-zero exit code: 2
1:05:25 PM: Failing build: Failed to build site
1:05:25 PM: Finished processing build request in 28.901s
1:05:25 PM: Failed during stage "building site": Build script returned non-zero exit code: 2