fix: backend/package.json & backend/package-lock.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-MULTER-15365916
- https://snyk.io/vuln/SNYK-JS-MULTER-15365918

backend/package-lock.json

@@ -12,7 +12,7 @@
         "cors": "^2.8.5",
         "express": "^4.22.2",
         "fs-extra": "^11.2.0",
-        "multer": "^2.0.2",
+        "multer": "^2.1.0",
         "path": "^0.12.7",
         "socket.io": "^4.8.1",
         "sqlite3": "^6.0.1",
@@ -4315,18 +4315,6 @@
         "node": ">= 18"
       }
     },
-    "node_modules/mkdirp": {
-      "version": "0.5.6",
-      "resolved": "https://registry.npmjs.org/mkdirp/-/mkdirp-0.5.6.tgz",
-      "integrity": "sha512-FP+p8RB8OWpF3YZBCrP5gtADmtXApB5AMLn+vdyA+PyxCjrCs00mjyUozssO33cwDeT3wNGdLxJ5M//YqtHAJw==",
-      "license": "MIT",
-      "dependencies": {
-        "minimist": "^1.2.6"
-      },
-      "bin": {
-        "mkdirp": "bin/cmd.js"
-      }
-    },
     "node_modules/mkdirp-classic": {
       "version": "0.5.3",
       "resolved": "https://registry.npmjs.org/mkdirp-classic/-/mkdirp-classic-0.5.3.tgz",
@@ -4340,21 +4328,22 @@
       "license": "MIT"
     },
     "node_modules/multer": {
-      "version": "2.0.2",
+      "version": "2.1.0",
-      "resolved": "https://registry.npmjs.org/multer/-/multer-2.0.2.tgz",
+      "resolved": "https://registry.npmjs.org/multer/-/multer-2.1.0.tgz",
-      "integrity": "sha512-u7f2xaZ/UG8oLXHvtF/oWTRvT44p9ecwBBqTwgJVq0+4BW1g8OW01TyMEGWBHbyMOYVHXslaut7qEQ1meATXgw==",
+      "integrity": "sha512-TBm6j41rxNohqawsxlsWsNNh/VdV4QFXcBvRcPhXaA05EZ79z0qJ2bQFpync6JBoHTeNY5Q1JpG7AlTjdlfAEA==",
       "license": "MIT",
       "dependencies": {
         "append-field": "^1.0.0",
         "busboy": "^1.6.0",
         "concat-stream": "^2.0.0",
-        "mkdirp": "^0.5.6",
+        "type-is": "^1.6.18"
-        "object-assign": "^4.1.1",
-        "type-is": "^1.6.18",
-        "xtend": "^4.0.2"
       },
       "engines": {
         "node": ">= 10.16.0"
+      },
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/express"
       }
     },
     "node_modules/napi-build-utils": {
@@ -6287,15 +6276,6 @@
         }
       }
     },
-    "node_modules/xtend": {
-      "version": "4.0.2",
-      "resolved": "https://registry.npmjs.org/xtend/-/xtend-4.0.2.tgz",
-      "integrity": "sha512-LKYU1iAXJXUgAXn9URjiu+MWhyUXHsvfp7mcuYm9dSUKK0/CjtrUwFAxD82/mCWbtLsGjFIad0wIsod4zrTAEQ==",
-      "license": "MIT",
-      "engines": {
-        "node": ">=0.4"
-      }
-    },
     "node_modules/y18n": {
       "version": "5.0.8",
       "resolved": "https://registry.npmjs.org/y18n/-/y18n-5.0.8.tgz",

backend/package.json

@@ -15,7 +15,7 @@
     "express": "^4.22.2",
     "socket.io": "^4.8.1",
     "cors": "^2.8.5",
-    "multer": "^2.0.2",
+    "multer": "^2.1.0",
     "sqlite3": "^6.0.1",
     "uuid": "^11.1.1",
     "path": "^0.12.7",