feat: enable prompt caching for gemini-2.5-flash-preview-05-20 (#3907)

* feat: enable prompt caching for gemini-2.5-flash-preview-05-20

* feat: Add cache pricing for gemini-2.5-flash-preview-05-20 models

Author: shariqriazz

src/shared/api.ts

@@ -529,7 +529,7 @@ export const vertexModels = {
 		maxTokens: 65_535,
 		contextWindow: 1_048_576,
 		supportsImages: true,
-		supportsPromptCache: false,
+		supportsPromptCache: true,
 		inputPrice: 0.15,
 		outputPrice: 3.5,
 		maxThinkingTokens: 24_576,
@@ -540,7 +540,7 @@ export const vertexModels = {
 		maxTokens: 65_535,
 		contextWindow: 1_048_576,
 		supportsImages: true,
-		supportsPromptCache: false,
+		supportsPromptCache: true,
 		inputPrice: 0.15,
 		outputPrice: 0.6,
 	},
@@ -772,9 +772,11 @@ export const geminiModels = {
 		maxTokens: 65_535,
 		contextWindow: 1_048_576,
 		supportsImages: true,
-		supportsPromptCache: false,
+		supportsPromptCache: true,
 		inputPrice: 0.15,
 		outputPrice: 3.5,
+		cacheReadsPrice: 0.0375,
+		cacheWritesPrice: 1.0,
 		maxThinkingTokens: 24_576,
 		supportsReasoningBudget: true,
 		requiredReasoningBudget: true,
@@ -783,9 +785,11 @@ export const geminiModels = {
 		maxTokens: 65_535,
 		contextWindow: 1_048_576,
 		supportsImages: true,
-		supportsPromptCache: false,
+		supportsPromptCache: true,
 		inputPrice: 0.15,
 		outputPrice: 0.6,
+		cacheReadsPrice: 0.0375,
+		cacheWritesPrice: 1.0,
 	},
 	"gemini-2.5-pro-exp-03-25": {
 		maxTokens: 65_535,