fix(deps): update dependency postcss-loader to ^7.3.0 for gatsby-plugin-postcss (#38021)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

packages/gatsby-plugin-postcss/package.json

@@ -8,7 +8,7 @@
   },
   "dependencies": {
     "@babel/runtime": "^7.20.13",
-    "postcss-loader": "^7.1.0"
+    "postcss-loader": "^7.3.0"
   },
   "devDependencies": {
     "@babel/cli": "^7.20.7",

yarn.lock

@@ -8337,7 +8337,7 @@ cosmiconfig@^7.0.0:
     path-type "^4.0.0"
     yaml "^1.10.0"
 
-cosmiconfig@^8.0.0:
+cosmiconfig@^8.1.3:
   version "8.1.3"
   resolved "https://registry.yarnpkg.com/cosmiconfig/-/cosmiconfig-8.1.3.tgz#0e614a118fcc2d9e5afc2f87d53cd09931015689"
   integrity sha512-/UkO2JKI18b5jVMJUp0lvKFMpa/Gye+ZgZjKD+DGEN9y7NRcf/nK1A0sp67ONmKtnDCNMS44E6jrk0Yc3bDuUw==
@@ -14455,6 +14455,11 @@ jest@^29.4.1:
     import-local "^3.0.2"
     jest-cli "^29.4.1"
 
+jiti@^1.18.2:
+  version "1.18.2"
+  resolved "https://registry.yarnpkg.com/jiti/-/jiti-1.18.2.tgz#80c3ef3d486ebf2450d9335122b32d121f2a83cd"
+  integrity sha512-QAdOptna2NYiSSpv0O/BwoHBSmz4YhpzJHyi+fnMRTXFjp7B8i/YG5Z8IfusxB1ufjcD2Sre1F3R+nX3fvy7gg==
+
 joi@^14.3.1:
   version "14.3.1"
   resolved "https://registry.yarnpkg.com/joi/-/joi-14.3.1.tgz#164a262ec0b855466e0c35eea2a885ae8b6c703c"
@@ -18669,12 +18674,13 @@ postcss-loader@^5.3.0:
     klona "^2.0.4"
     semver "^7.3.4"
 
-postcss-loader@^7.1.0:
-  version "7.1.0"
-  resolved "https://registry.yarnpkg.com/postcss-loader/-/postcss-loader-7.1.0.tgz#3ba0dfddff06043f3eac7690a1d8b432264bb866"
-  integrity sha512-vTD2DJ8vJD0Vr1WzMQkRZWRjcynGh3t7NeoLg+Sb1TeuK7etiZfL/ZwHbaVa3M+Qni7Lj/29voV9IggnIUjlIw==
+postcss-loader@^7.3.0:
+  version "7.3.0"
+  resolved "https://registry.yarnpkg.com/postcss-loader/-/postcss-loader-7.3.0.tgz#05991c1e490d8ff86ef18358d87db3b5b2dcb5f5"
+  integrity sha512-qLAFjvR2BFNz1H930P7mj1iuWJFjGey/nVhimfOAAQ1ZyPpcClAxP8+A55Sl8mBvM+K2a9Pjgdj10KpANWrNfw==
   dependencies:
-    cosmiconfig "^8.0.0"
+    cosmiconfig "^8.1.3"
+    jiti "^1.18.2"
     klona "^2.0.6"
     semver "^7.3.8"