Extract url for scripts into variable (#141)

## Which problem is this PR solving?
- part of jaegertracing/jaeger#6570

## Description of the changes
- extracted`
https://raw.githubusercontent.com/jaegertracing/jaeger/main/scripts`
into a variable `$(SCRIPTS_URL)`
#121 (comment)

## How was this change tested?
- 

## Checklist
- [X] I have read
https://github.com/jaegertracing/jaeger/blob/master/CONTRIBUTING_GUIDELINES.md
- [x] I have signed all commits
- [x] I have added unit tests for the new functionality
- [x] I have run lint and test steps successfully
  - for `jaeger`: `make lint test`
  - for `jaeger-ui`: `npm run lint` and `npm run test`

Signed-off-by: danish9039 <danishsiddiqui040@gmail.com>

Makefile

@@ -1,5 +1,6 @@
 # Copyright (c) 2023 The Jaeger Authors.
 # SPDX-License-Identifier: Apache-2.0
+SCRIPTS_URL = https://raw.githubusercontent.com/jaegertracing/jaeger/main/scripts
 
 JAEGER_IMPORT_PATH = github.com/jaegertracing/jaeger-idl
 
@@ -228,9 +229,9 @@ lint-imports: setup-lint-scripts
 .PHONY: setup-lint-scripts
 setup-lint-scripts:
 	@mkdir -p .scripts/lint
-	@curl -s -o .scripts/lint/import-order-cleanup.py https://raw.githubusercontent.com/jaegertracing/jaeger/main/scripts/lint/import-order-cleanup.py
+	@curl -s -o .scripts/lint/import-order-cleanup.py $(SCRIPTS_URL)/lint/import-order-cleanup.py
 	@chmod +x .scripts/lint/import-order-cleanup.py
-	@curl -s -o .scripts/lint/updateLicense.py https://raw.githubusercontent.com/jaegertracing/jaeger/main/scripts/lint/updateLicense.py
+	@curl -s -o .scripts/lint/updateLicense.py $(SCRIPTS_URL)/lint/updateLicense.py
 	@chmod +x .scripts/lint/updateLicense.py
 
 .PHONY: fmt